Central Auditory System and Central Auditory Processing Disorders: Some Conceptual Issues

Dennis P. Phillips, Ph.D.1

ABSTRACT

The central auditory system has both parallel and hierarchical afferent architectures. In the frequency domain, it is tonotopically constrained, and in the spatial domain, it is dominated by a representation of the contralateral acoustic hemifield. The functions supported by the afferent pathways can be somewhat overlapping, and the connectivity among the pathways is to some degree plastic. Partial deafferentation (in the form of high-frequency hearing loss) and behavioral experience are capable of causing alterations in tonotopic maps in the more rostral auditory system, even in adult animals. Central auditory processing is often frequency- specific. The temporal processes needed for normal auditory function are diverse, which is to be expected given the heterogeneous ways in which auditory events are disposed in time and encoded neurally. Central auditory pathologies need not respect structural or functional boundaries in the brain, and so should be expected to have idiosyncratic presentations. Man- agement strategies based on auditory training may exploit basic neuroplasticity, but more evidence is needed to substantiate any hypothesis of their differential efficacy in remediation of central auditory processing disorders or language and reading problems.

KEYWORDS: Auditory neuroscience, neural representation, neural plasticity, temporal processing, perceptual architecture, auditory training

Learning Outcomes: Upon completion of this article, the reader will (1) understand the basic design principles of the central auditory pathway, factors that can trigger plastic responses of the central auditory system, and the forms that those responses take; (2) comprehend the diverse range of functions embraced by the term central auditory processing, and the many levels at which specifically temporal processes contribute to hearing; and (3) appreciate some of the issues surrounding auditory training paradigms and their effectiveness.

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Dennis P. Phillips, Ph.D., Professor, Hearing Research Laboratory, Department of Psychology, Dalhousie University, Halifax, NS, Canada B3H 4J1. E-mail: [email protected]. 1Hearing Research Laboratory, Department of Psychology, Dalhousie University, Halifax, Nova Scotia, Canada. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,251,262,ftx,en;sih00219x. 251 252 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

An important key in coming to an ana- That information is then disseminated within lytic understanding of central auditory pro- three divisions of the cochlear nuclear com- cessing (CAP) and its disorders (CAPDs) is plex, and from there to a host of caudal audi- the complexity and dynamism of the central tory brainstem nuclei. Almost all of those pro- auditory nervous system (CANS) itself. The jections are strictly topographic, that is, they brain, of which the CANS is a relatively small preserve the general tonotopy (i.e., the spatial but highly integrated part, is even more com- arrangement of neurons according to the fre- plicated and dynamic. This architectural com- quency to which they are most sensitive) devel- plexity is what supports the diversity of central oped in the cochlea, and connections within auditory function and the brain’s capacity for more central nuclei are usually sufficiently local adaptation and learning. Consider the fol- to preserve (or enhance) the fine frequency lowing: the brain must support the detection, tuning of individual neurons. discrimination and localization of sound, the The divergent projection of the cochlear segregation of auditory figure from ground, per- nerve on the cochlear nucleus begins a pattern ceptual learning within new or familiar audi- of parallel processing, in the sense that afferent tory dimensions, recognition and identification information from the same cochlear sources is of the source, introspection about the perceived received and processed, largely independently, sound, and so on. by three nuclei at the same time. Those nuclei The detail of our neurophysiologic de- participate in separable and identifiable neural scriptions of CANS function and behavioral circuits. Some of them are involved in binaural descriptions of CAP is growing, as is our com- spatial hearing. Thus, some nuclei of the su- prehension of the links between those two lev- perior olivary complex receive tonotopically els of description. With these advances are constrained inputs from both ventral cochlear coming new insights into CAPDs in terms of nuclei and, through those routes, can serve as both their genesis and their phenomenology coincidence detectors for the timing and am- and, in turn, there is an emergence of new ways plitudes of stimuli at the two ears. Those inter- of thinking about management and remedia- aural parameters in turn are cues to sound tion. Because much of this information is new, source location in the horizontal plane. In this and because it barely scrapes the surface of the way, we see the development of hierarchical system’s structural and functional architecture, processing, because the convergence of input re- much of our understanding is still at a concep- sults in a serial growth in response complex- tual level. The purpose of this article is to ity—from a code for the timing and amplitude sketch some of these advances, to illustrate their of events at a given ear, to a cross-correlation of strengths and importance, and to make cau- those encoded events at the two ears. tionary remarks about some of them. What fol- The cells of the olivary nuclei do not just lows is, of necessity, a somewhat personal view inherit the properties of their inputs, but exe- that is not intended to cover all aspects of these cute operations on those inputs so that a new issues; it does assume a basic knowledge of the representation emerges. In this instance, the rep- CANS and CAP. resentation is of the interaural cues for source location, and because this is done within tonotopically constrained architecture, it follows THE CENTRAL AUDITORY that the processing is done on a frequency-by- NERVOUS SYSTEM frequency basis. There is an important behavioral outcome of this. As it happens, the magni- The afferent sensory input to the CANS is the tude of the interaural disparities in time and array of cochlear nerve cell axons from each of intensity vary not only with the eccentricity of the two ears. The cochlear transduction pro- the sound source, but also with frequency. Sound cess confers on each afferent fiber narrow fre- sources that are wideband in spectrum thus pro- quency tuning, and it is the role of each fiber to vide a rich supply of information about source encode the presence, amplitude and timing of location and, because the interaural disparity stimulus energy within its frequency passband.1,2 information is encoded tonotopically, the fre- CAS AND CAPD: CONCEPTUAL ISSUES/PHILLIPS 253 quency-specificity of the information is pre- patchy mosaic of smaller territories dedicated served in the brain. This provides a rich neural to other facets of stimulus representation (lo- representation from which to derive a percep- cation, amplitude, bandwidth, periodicity, and tual judgement, and it is for these reasons that so on). Second, many of the circuits in the af- behavioral sound localization acuity is far more ferent pathway have overlapping functions. acute for wideband sources than for tonal ones Thus, binaural convergence that initially occurs that provide only a single time and/or intensity in the superior olivary nuclei also may occur de disparity at the ears. novo in the auditory midbrain (and as far ros- The outputs of the olivary nuclei and the tral as the cortex5). These patterns of connec- projections of some cell groups within the tivity make it difficult to assign a unique locus cochlear nuclei are sent to the nuclei of the lat- to any particular central auditory function. It is eral lemniscus and/or to the inferior colliculus probably because of the multiple layers of bin- (auditory midbrain). Some of these projections aural interaction that lesion of the olivary nu- also are parallel in organization. For example, clei can leave the patterns of binaural input to the lateral superior olive projects contralater- cortical neurons nearly normal.6 Whether such ally upon both the dorsal nucleus of the lateral inputs can support normal neurophysiologic lemniscus and the inferior colliculus (with the coding of interaural disparity cues in the cortex former then projecting on to the latter). There currently is unknown. is also a hierarchical arrangement in this level of the projections, because some individual neurons of the inferior colliculus receive, for CENTRAL REPRESENTATIONS, example, input from both the dorsal cochlear PLASTICITY, AND BEHAVIORAL nucleus and the lateral superior olive, and thus PERFORMANCE inherit the properties of both.3 The inferior colliculus ultimately receives input from the There is some degree of plasticity in the pat- cochlear nuclei, olivary nuclei, and nuclei of terns of auditory afferent connectivity. Perhaps the lateral lemniscus. These inputs are often the most dramatic expressions of this have come bilateral, but the excitatory or inhibitory nature from studies in animals with neonatal cochlear of the connectivity is of a kind that preserves ablations in whom there can be marked re- and/or refines the sensitivity to interaural cues arrangement of connections from the surviving for sound location.2 The inferior colliculus pro- ear.7 The striking complexity of the brainstem jects on the thalamic medial geniculate body, pathways offers numerous opportunities for local which then supplies the afferent input to the shuffling of connections following neonatal auditory cortex. There is also a well-developed ablations. Thus, in the absence of input from descending auditory pathway.4 This includes one ear to the medial superior olive, the intact dense cortico-thalamic and cortico-collicular ear may come to innervate both sides of the connections, and other pathways descending nucleus. Projections of this sort appear to be from the brainstem ultimately to the cochlear able to support physiological responses more outer hair cells. rostrally. There are two further principles of organi- The internal organization of tonotopic zation to be revealed here. One is that the con- maps in the adult CANS also can be influenced vergence of input onto the inferior colliculus by partial (i.e., frequency specific) cochlea dam- usually continues to respect tonotopy and is age. Most often, this damage has been to basal not undifferentiated: there are local territories cochlear sectors, and changes to central tono- dominated (anatomically and physiologically) topy have taken the form of a loss of neural by afferents from only a subset of those poten- space devoted to the lesioned cochlear sector, tially available. These patchy territories are pre- and a nearly equivalent expansion of the terri- served (or renewed) in the auditory thalamus tory allocated to peri-lesional cochlear places and cortex, with the result that the primary (i.e., cochlear sites adjacent to the damaged sec- auditory cortex has been conceptualized as a tor).8 This form of plasticity is probably differ- single tonotopic array on which is imposed a ent to that following wholesale neonatal cochlear 254 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

ablations, because it is present in adulthood, ual differences in the details of auditory repre- and because it is expressed within nuclei rather sentations and in behavioral performance. than a rearrangement of connectivity between These kinds of observations tend to prompt pathways. The changes to the affected parts of a “bigger is better” view of brain function (i.e., the tonotopic maps have at least two stages. that a greater volume of neural tissue devoted The earlier stage is a loss of sensitivity to stim- to a particular function necessarily enhances ulation of the affected cochlear sector, and performance of that function). We already have what residual responsiveness remains is of the seen evidence compatible with this view (see kind expected from a pathological endorgan the previous discussion). On the other hand, (high thresholds, broad frequency tuning). The there are also counter-examples. Monocular de- later stage is the development of near-normal privation of animals during the critical period sensitivity to acoustic stimulation, but from the results in the deprived eye receiving little or no peri-lesional cochlear places (with near-normal cortical representation (and blindness through frequency tuning for innervation from that that eye), while the nondeprived eye presum- cochlear site). Note that this re-innervation does ably receives twice the cortical postsynaptic not support a recovery of behavioral sensitivity space that it normally would. Despite this, there to stimulation at the frequencies deprived of is little evidence for behavioral superiority in cortical representation (discussed later in this spatial acuity through the nondeprived eye over article). that seen in normal animals. Likewise, we saw Plasticity in the adult thalamocortical au- above that in animals, restricted high-frequency ditory system can be driven by peripheral events hearing loss can result in an expanded repre- far less dramatic than ablations. Thus, the be- sentation of peri-lesional frequencies. We have havioral training on a frequency discrimination every reason to believe that this plasticity ex- task using tonal stimuli can exert plastic changes tends to persons with high-frequency hearing on cortical tonotopic maps, notably by expand- loss. Nevertheless, in the face of any such plas- ing the territories devoted to the frequencies ticity, while it is no surprise that auditory acuity involved in the training.9 Such changes likely for sounds activating the damaged cochlear sec- depend on cholinergic influences from the nu- tor may be poorer than normal, there is little cleus basalis,10,11 perhaps by influencing activ- evidence to support the existence of greater- ity in the neural loop formed by afferents flow- than-normal frequency acuity for peri-lesional ing from the midbrain through the thalamus to frequencies.13 the cortex on the one side, and efferents from The foregoing observations raise fascinat- the cortex to the thalamus and colliculus on the ing questions about the nature and extent of other. Through this feedback loop, there may plastic mechanisms in the CANS. The two be a way for the thalamocortical auditory sys- cases described in the previous paragraph are tem to “select” afferent inputs12 of most behav- instances in which the provision of greater- ioral significance and provide them the most than-usual neural substrate failed to enhance elaborate representation. In this regard, it is behavioral performance above normal. It can typically an expansion of the cortical territory be argued that the naturally-occurring visual allocated to the relevant sector of the cochlea spatial acuity in the normal animal is already that accompanies behavioral training of func- evolutionarily optimized to be as great as is tion at that cochlear sector and, of the neuro- neurologically supportable, and that through physiologic (representational) changes that occur, years of exposure to speech (and music, etc.) it is the size of the representation that is most frequency discrimination in man has become a strongly correlated with behavioral acuity.9 highly over learned task. The latter may not be The further implication of this line of work is true of animals, and it may be for this reason that if the details of cortical (or other) auditory that we see the demonstrable effects of audi- representations are somewhat experience-de- tory frequency discrimination training in ani- pendent, then it follows that individual differ- mals. From the basic science standpoint then, ences in experience will be reflected in individ- it would be valuable to ascertain whether train- CAS AND CAPD: CONCEPTUAL ISSUES/PHILLIPS 255 ing in a non-over-learned task (e.g., temporal Two related features of specifically spatial interval discrimination) in a frequency range coding have emerged in the last two decades. with an exaggerated central representation (as One is that, for centers rostral to the olivary in peri-lesional frequencies in the case of re- nuclei, neurons that have restricted spatial restricted high-frequency hearing loss) would sup- ceptive fields tend to have those receptive fields port better acuity than the same training in a located in the contralateral auditory hemifield.21 frequency range with a normal central repre- The medial borders of these receptive fields are sentation. Perhaps a more interesting clinical usually within about 30 degrees of the midline, question concerns the prospects for training in and are probably determined by binaural inter- individuals who at the outset have an impover- actions. Neural response rate for locations within ished neurological substrate of some cochlear the receptive field are shaped more heavily by sector or auditory function. In this general re- the directionality of the pinna within that gard, developmental dyslexics often have—in hemifield. Second, it has become clear that each addition to pathological left superior temporal side of the CANS is independently capable of plana—larger-than-normal right plana,14 sug- localizing sound sources in the contralateral gesting that an excess of language substrate auditory hemifield. Each cerebral hemisphere (whether occurring independently or as a com- contains the spatial information required for pensatory response to the left-sided abnormal- localizing sources in the contralateral hemi- ity) has still left the patients with poor reading field, and unilateral forebrain lesions usually performance. result in deficits in sound localization behavior only for sources in the auditory hemifield contralateral to the lesion.21,22 Psychophysical evidence suggests that the human auditory system CENTRAL AUDITORY PROCESSING probably has spatial perceptual channels with a hemifield architecture.23 The mechanisms in As alluded to at the beginning of the article, which these hemifield-tuned perceptual chan- CAP is an umbrella term for all of the opera- nels have their genesis are still being worked tions executed on peripheral auditory inputs, out. The revelation of the hemifield architec- and which are required for the successful and ture may offer new insights into a host of audi- timely generation of auditory percepts, their tory spatial phenomena, including cocktail party resolution, differentiation, and identification. effects, spatial masking, and so on. Note that Many of the low-level analyses of sound are the two-channel (left and right) hemifield ar- based on frequency-specific processing; these chitecture of perceptual channels for space is analyses include sound localization (discussed quite different to that for the frequency di- previously; also see Jenkins and Merzenich15), mension—the latter is subject to a multiple- temporal gap detection,16 temporal modulation channel (critical band) processing architecture. detection,17 and loudness perception.18 It also The concept of channels is important; it is clear that more high-level processes (e.g., se- includes the complete neural representation of lective auditory attention) can operate locally the stimulus and the perceptual structure sup- in frequency space,19 and that others are con- ported by that representation.16,24 Auditory strained by frequency (e.g., auditory stream processing that is within-channel can often be segregation20). The tonotopic architecture of thought of as low-level or automated and with the CANS receives behavioral expression in relatively little cognitive overhead. Thus, the frequency-specificity of much central auditory detection of temporal gaps between identical processing. Sensory information processing is markers is done effortlessly and with great acu- executed on a frequency-by-frequency basis ity. In contrast, the detection of temporal gaps (see the previous discussion), and the alloca- between dissimilar markers (between-channel tion of sensory signals to perceptual streams gap detection) is more labor-intensive, subject (perceptual grouping) has frequency as a prin- to a longer learning curve, and has poorer acu- cipal guiding force. ity.16,23 This difference may exist because the 256 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

existence of channel architecture normally groups the clicks as a single object on the basis obliges the allocation of attentional resources of the perfectly regular inter-click intervals, and selectively to one channel at a time.16,20,23 By having made that grouping process, assigns to the same reasoning, perceptual operations ex- the middle clicks of the train spatial locations plicitly requiring a comparison of activity in that are intermediate between those of the an- different channels (e.g., relative timing opera- chor point clicks. One level of temporal analy- tions) have poor acuity. sis (interaural time disparity coding) perceptu- A vast number of central auditory pro- ally anchors the endpoints of the click train, cesses rely on a specifically temporal analysis of while a second level of analysis (grouping by the incoming signal. The temporal coincidence inter-click interval) ultimately results in the per- of events that facilitates their perceptual group- ceptual illusion. ing as an auditory object, the segregation of au- Temporal processes in audition are not re- ditory figure and ground by temporal streaming stricted to the accurate encoding of the stimulus processes, the discrimination of phonemes dif- time structure, and the generation of veridical fering only in some temporal aspect (e.g., dura- percepts from that encoding. The generation of tion or voice onset time), rhythm perception, the percept itself takes time, and there is proba- temporal order judgments and sequencing, and bly a host of operations performed on sensory periodicity pitch perception are all examples that inputs that take place during that time, and to may have their mechanisms rooted deeply in which we have little or no direct perceptual ac- central temporal representations of sounds. It is cess.26–28 It is the distribution in time of auditory important to understand that these temporal sensory and subsequent linguistic and cognitive phenomena are not reflections of some single processes that makes possible the use of event- process. Thus, the fidelity with which the audi- related evoked potentials to track the time course tory forebrain represents the timing of onset of that processing. Because of the diversity of transients and temporal periodicities are deter- temporal processes in audition, identifying a mined relatively independently.25 Multiple lev- process (or a disorder) simply as temporal may els of temporal processing might be involved in not be helpful. an apparently single perceptual operation. A high-level process might exploit the output of a low-level one. One example of this is the segregation of two sound sources with different peri- CENTRAL AUDITORY PROCESSING odicity pitches on the basis of their different DISORDERS AND THEIR rhythms.20 A second is the erroneous grouping MANAGEMENT of two spatially-separated sounds as a single one on the basis of a contiguous periodicities, as CAPDs are probably as idiosyncratic as the in- in auditory saltation.26,27 In this paradigm, di- dividuals they affect. Most of the CAPDs seen chotic clicks are presented in trains of 6 or 8 in the clinic will not have their origins localiz- elements at perfectly regular intervals; the first able at a structural level. The exceptions are half of the clicks favor one ear (or side) on the usually rare accidental cases in which precise basis of an interaural time difference, while the delineation of the structural and functional pa- last half of the elements favor the other ear (or thologies have been possible and tremendously side). For inter-click intervals less than about informative. For many of the auditory percep- 120 ms, the resulting percept is of clicks ema- tual dimensions we can imagine, there have been nating not only from the sites of stimulation, single-case studies revealing isolated functional but also from points between them, as if a sin- loss following focal cerebral lesion. These in- gle source were moving along a trajectory be- clude deficits in sound localization,29 auditory tween the click train’s anchor points. One ac- motion perception,30 frequency discrimination,31 count of the mechanism is thus that the anchor melody perception,32 and various components points of the train have locations defined by in- of auditory, phonological or other levels of analy- teraural time differences; the auditory system sis of spoken language.33 CAS AND CAPD: CONCEPTUAL ISSUES/PHILLIPS 257

It is probably much more common for one needs to know whether any auditory prob- CAPDs to be highly idiosyncratic, and there is lem is a component of a supramodal processing a host of reasons for this to be true. One is that problem.36 Third, temporal processing problems central nervous system pathology, whether de- might be markers for, or causally related to, lan- velopmental or acquired, need not respect func- guage impairments.28 In the classical connec- tional neurological boundaries. A subtle orga- tionist view of language function, poor auditory nizational abnormality in the development of receptive language function was an unremark- neural connections, or a transient metabolic able consequence of an acquired impoverished problem during a critical period for the incor- input to the language processor. In a develop- poration of certain membrane channel proteins, mental scenario (following the general line of could have diverse presentations, precisely be- argument provided by Tallal et al37 and Fitch et cause the deficit may be relatively scattered in al38), a poor perceptual processor might affect neural space. Second, even in the case of focal not only the acquisition of normal auditory re- lesions, we need to remember that brains are ceptive language, but through that mechanism, themselves somewhat individual. In both ani- provide poor targets to guide the development mals and man, the primary auditory cortex is of speech production and phonology. This is located in tissue that varies in fissural pattern not to imply that all developmental language between individuals.34,35 There is some likeli- disorders are cascade error sequelae to low-level hood that functional territories will not respect perceptual problems. One view is that many fissural boundaries in any case.34 It is much cases of developmental language delay result more likely that functional territories will be from various forms of synergism between many tied to cytoarchitectonic ones. Third, for a given factors, of which an auditory processing prob- functional territory, there may be individual lem is only one.39 differences in the fine detail of structure and Comprehensive evaluation of persons with organization, and different propensities for suspected CAPDs is not a small task. Given adaptation and recovery; so similarly located the wealth of auditory functions ascribed to abnormalities might have different behavioral the brain, it should come as no surprise that a sequelae in different individuals. Because so wealth of assessment is needed to assay those much of auditory perceptual experience is based functions. It also raises the prospect that the on the time structure of sounds and because evaluation itself might require tools that are there are many levels of sound time structure not currently available. In this regard, there are to be processed, some sort of temporal process- increasing numbers of reports using auditory ing problem will be common in CAPD pre- assessments that are not part of the standard sentation. audiologic battery (e.g., various forms of tem- From a practical standpoint, specification poral gap detection, backward masking,39,40 au- of a subtle neurological abnormality that un- ditory stream segregation,41 auditory saltation42). derlies some processing deficit may not be as Currently, this may appear a source of frustra- immediately helpful as a detailed mapping of tion because the nonstandardized testing makes the functional disability itself. The tremendous it hard to compare studies, either for the relia- range of functions ascribed to the CANS, and bility with which separate studies have probed individual differences in their relative develop- the same mechanism, or because different stud- ment, means that we require probes sensitive ies may, by design, not be probing the same to each function. Probing of auditory function temporal mechanisms. In practice however, this should be done in the context of a much more is often the state of a young science and any general interrogation of sensory, linguistic, and standardization of test materials that is appro- cognitive capacities. This is for a number of rea- priate will emerge as the scientific issues sort sons. First, more high-level cognitive impair- themselves out over time. ments might impair performance on auditory There is growing interest in the manage- processing probes without necessarily being in- ment of developmental language delay through dicative of impairments in the latter. Second, intensive training strategies designed to reme- 258 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

diate central auditory processing disorders that tory levels of analysis. The development of Fast might underlie the language delay.43,44 Perhaps ForWord, and discussion of its effectiveness, the most well-known of these is Fast ForWord.45 thus stands in contrast to other interventions The training is based on the premise that brief, that more explicitly acknowledge that they cap- closely-spaced acoustic events (of the temporal italize on the contributions of language compo- grain required to distinguish some phonemes33) nents of the training.47–49 are perceptually differentiated relatively poorly Initial reports of the effectiveness of Fast in language-learning impaired children and that ForWord training on auditory temporal process- this results in poor phonology. The hope is, ing43 showed great advantage over equivalently therefore, that provided with a more appropri- time-intensive classical language training and ately differentiated (i.e., trained) auditory input, nonadaptive auditory intervention. Language an otherwise intact language processor (or one outcome44 was significantly superior for a group which itself adapts to the new inputs) will have receiving adaptive training with the modified an improved output. Fast ForWord43–45 uses speech than for a control group receiving expo- stimuli in which target elements (e.g., stop sure to natural stimuli in a nonadaptive fashion. consonants in speech stimuli) are selectively More recently, independent studies have lengthened in time and amplified, and in which produced mixed findings. One group using a the sounds to be discriminated are presented at Fast ForWord-like program has confirmed that programmed inter-stimulus intervals (ISIs). The perceptual training with speech materials can training is adaptive, in the sense that as the improve perceptual performance with those child learns to perform auditory discriminations materials50 and may improve phonologic aware- within stimulus pairs, the extent of the tempo- ness.51 The former study50 did not employ a ral stretching, the amplification, and the ISI all control group, so conclusions about the speci- can be reduced.The training also includes com- ficity of any benefit for that training program ponents above the level of acoustics, notably cannot be drawn. Another study group reported exercises that target word recognition, auditory that it was unclear whether Fast ForWord train- memory and language comprehension. ing had any effects on language outcome above Evaluating Fast ForWord or other training those seen with other, specifically language- programs is necessarily a complex issue.46 First, based training programs.52 However, the par- if a training program targets both auditory and ticipant population in that study had been se- linguistic levels of analysis, but measures out- lected on the basis of reading difficulties, rather come using language performance, then it is than on the basis of the existence of auditory not immediately clear which component(s) of processing difficulties. This is important, be- the training are responsible for the outcome. cause dyslexia itself is something of an um- Second, if a training program is predicated on brella category, and it is not clear that all forms an account of language-learning disability that of dyslexia (or language impairments) are nec- is true for only a subset of affected listeners, then essarily associated with CAPD.28,39,53,54 participant selection in outcome studies is im- Recently, there have been a series of case portant—because negative outcomes in non- reports published on the outcome of Fast For- relevant participants have little bearing on the Word training on language55,56 and auditory per- question. Third, the differential effectiveness ceptual57,58 performance. Each study was based of a training program or other intervention de- on small numbers of participants and so must pends critically on appropriate control for par- be regarded as preliminary in its findings. ticipants’ attention, motivation, duration of With that caveat, the reports had some poten- treatment, and so on across the independent tially important conclusions beyond that Fast treatment variable. The issue of Fast ForWord’s ForWord training may improve auditory pro- effectiveness has become theoretically impor- cessing or language performance in some par- tant because of the hypothesized origins of de- ticipants. One is that language outcome fol- velopmental language delay in specifically audi- lowing participation in a training program may CAS AND CAPD: CONCEPTUAL ISSUES/PHILLIPS 259 be independent of the level of language pro- REFERENCES cessing targeted by the training.56 It follows from this that the effectiveness of Fast For- 1. Ruggero MA. 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Plasticity, Auditory Training, and Auditory Processing Disorders

Frank E. Musiek, Ph.D.,1 Jennifer Shinn, M.S.,2 and Christine Hare, M.A.1

ABSTRACT

Auditory training (AT) for the treatment of auditory processing disorders (APD) has generated considerable interest recently. There is emerging evidence that well conceived AT programs can improve higher auditory function. The plasticity of the brain underlies the success of AT. This article reviews brain plasticity and the role of plasticity in AT outcomes, and highlights key studies that provide insight into the clinical use of AT for APD.

KEYWORDS: Auditory processing disorder, auditory training, plasticity

Learning Outcomes: Upon completion of this article, the reader will be able to (1) understand the rationale behind auditory plasticity as it applies to APD, (2) understand new therapy techniques for APD, and (3) formulate therapy approaches using plasticity.

Recently, there has been great interest in auditory nervous system (CANS). Improve- the use of auditory training (AT) for the treatment in higher auditory function is related to ment of auditory processing disorders (APD). the capacity of the central nervous system to The use of AT for peripheral auditory prob- change. This change is tightly linked to, and is lems is not a new concept, in that it has an ex- a result of, plasticity. This article reviews plas- tensive history.1 The use of AT for treatment ticity and AT within the framework of APD. of APD is new and its application is different from the classic use of AT. Most important to this difference is that AT applied to APD is AUDITORY PLASTICITY DEFINED targeting the brain as the main site of mediation, and the brain, unlike the auditory periph- There is a significant body of evidence from ery, is plastic. Though peripheral sensorineural both animals and humans that supports im- loss cannot be improved upon with AT, this provement in auditory tasks through the use of may not be the case for deficits of the central AT. As we begin to gain new insight into the

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Frank E. Musiek, Ph.D., Department of Communication Sciences and Otolaryngology, School of Medicine, University of Connecticut, Storrs, CT 06269. E-mail: [email protected]. 1Department of Communication Sciences and Otolaryngology, School of Medicine, University of Connecticut, Storrs, Connecticut; 2Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,263,276,ftx,en;sih00220x. 263 264 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

fundamental mechanisms involved in improved ner. This can be achieved by creating a conduc- performance on specific auditory tasks, we must tive loss, which is often done by plugging the take into consideration the concept of auditory ear and/or removing or damaging middle ear plasticity. The scientific literature on the sub- structures. Sensorineural hearing loss is experi- ject of plasticity is immense. For the purposes mentally created by exposing the ear to ototoxic of our discussion, we will concentrate specifi- drugs, high intensity noise, or mechanically cally on auditory plasticity and overview its re- damaging the cochlea. These hearing losses will lationship to AT. deprive the higher auditory system of stimula- Neural plasticity is defined by Lund2 as tion and will result in a reorganization of the “neural form and connections that take on a auditory cortex.3,8–10 Raising animals in acous- predictable pattern (probably genetically deter- tically attenuated chambers is another method mined) often referred to as neural specificity; of creating deprivation effects. High stimulation exceptions to this predictable pattern, in cer- or tasking of the auditory system is the other tain circumstances, represent neural plasticity.” condition that can create plastic changes in the Auditory (specific) plasticity can be defined as CANS.4,11 the alteration of nerve cells to better conform The barn owl is one of the most studied to immediate environmental influences, with animal models for demonstrating plasticity. this alteration often associated with behavioral One of the reasons for studying the barn owl is change.1 It is necessary for both clinicians and that its optic tectum (or midbrain), which is researchers to have a strong foundation in the similar in nature to the superior colliculus (SC) fundamentals of plasticity and its relationship of the mammal, contains neural substrate with to AT, as it is key to management of patients respect to both auditory and visual maps. The with APD. SC is one of the most highly studied cortical structures because of its ability to reorganize. The SC is a useful structure to investigate, as it ANIMAL RESEARCH is particularly sensitive to experience-dependent plasticity and alteration of auditory maps. The Perhaps the greatest body of evidence that sug- barn owl provides an extensive amount of mod- gests plasticity in the auditory system related eling information to base on the derivation of to training lies in the extensive number of ani- its auditory map.12 mal studies. Though the scope of this article Evidence of auditory plasticity has been does not allow extensive coverage of this topic, gained through both auditory deprivation and we will highlight a few studies that hopefully auditory training with the barn owl. Previous provide some principles of interest regarding deprivation studies, in which barn owls were plasticity. Some of the early research on plas- raised with monaural occlusion, provided phys- ticity and training via animal models focused iologic evidence of inter-aural level differences on sub-cortical levels and the brainstem; how- occurring in the posterior division of the ven- ever, the auditory cortex has recently gained tral nucleus of the lateral lemniscus within the considerable attention. The evidence of corti- brainstem.13 Through the use of acoustic filter- cal plasticity is shown impressively by func- ing devices, Gold and Knudsen14 investigated tional reorganization, that has attracted much the effect of altered auditory experience on inter- attention from scientists and clinicians in a va- aural timing differences of barn owls. Relative riety of disciplines. to owls raised under normal auditory conditions, Studies on rodents, monkeys, cats, and the owls raised with unilateral auditory deprivation avian species have shown reorganization within showed neuronal changes of the inferior col- the auditory cortex.3–7 There are two main con- liculus (in the optic tectum) and changes in be- ditions that can result in reorganization of the havioral responses, demonstrating that plasticity auditory cortex, sub cortex, and brainstem. One within the inferior colliculus plays a significant of these is deprivation that, experimentally, is role in adjustments in the inter-aural timing induced by creating hearing loss in some man- difference and frequency tuning. These plas- AUDITORY TRAINING PROGRAMS FOR APD/MUSIEK ET AL 265 tic changes in auditory experience as a result cantly with AT; however, complex tasks are of deprivation and accommodation are noted more likely to benefit as they necessitate more at both the subcortical12 and higher-level sys- brain function (and neural substrate) and, there- tems.15 fore, are more likely to benefit from brain plas- A substantial body of research suggests ticity.1 that reorganization takes place in all mammals. Generally there are two ways in which the These findings have strong implications for brain is thought to reorganize. Although both auditory plasticity in humans. The general find- require neuronal changes, their mechanisms ings show that sensory maps have training de- are quite different. Reorganization may involve pendent reorganization capabilities and sug- the activation of neurons and neural connec- gest that a majority, if not all of the brain, may tions that were previously in a state of rest.These be plastic.10 There also are indications that in reserve neurons replace the nonfunctional neu- mammals plasticity is lateralized. That is, cor- rons. That is, the reserve neurons would re- tical reorganization seems to take place in the place connections that are no longer active due hemisphere contralateral to the ear deprived of to damage or lack of stimulation.The other pro- acoustic input or for which there is peripheral posed mechanism underlying brain reorganiza- damage, which reduces peripheral input.10 tion requires that new connections be formed. Both mechanisms involve changes that may be slow and require an extensive amount of time MECHANISMS UNDERLYING and training, or the changes can be extremely CORTICAL PLASTICITY AND rapidly occurring through development and REORGANIZATION maturation without intervention.10 It should be noted that neural reorganiza- Before auditory plasticity and its relationship tion might not be considerable and obvious. to AT can be fully appreciated, there must be a According to Kaas,10 these structural changes comprehensive understanding of the mecha- may be rather subtle, resulting from modifica- nisms that underlie this critical process. Nu- tions in the extent of synaptic connections that merous theories have been proposed and the become more effective, or from changes in more widely accepted will be briefly discussed neural location, resulting in a more effective for the purpose of this review. targeting or spreading of axonal and dendritic It is well established that plastic changes are arbors, that in turn results in not only more but a result of neuronal responses to both external better located synaptic connections. If new stimuli (i.e., sounds in our environment) and dendrites are either being recruited or devel- internal stimuli (e.g., thinking about certain oped, their connections must be appropriate to sounds when we listen to music or read). We ensure that they evolve meaningful function. tend to think of our brain as a highly stable organ, when in fact it is its instability that we rely on most for development and auditory learning. CLINICAL CORRELATES There are generally three types of plasticity in OF AUDITORY PLASTICITY the auditory domain: (1) developmental plastic- IN HUMANS ity, (2) compensatory plasticity resulting from a lesion occurring somewhere within the auditory Clinical experience with hearing aids and system, and (3)learning-related plasticity.6 cochlear implants provide important insight Simple auditory tasks, such as detecting the and evidence of the plasticity phenomenon and presence of a pure tone, require relatively little raise several key questions as well. As mentioned neural substrate in the CANS. In contrast, com- previously, auditory reorganization can result plex tasks—such as discriminating small differ- from lack of input to central systems, usually ences among various acoustic stimuli in noise— after damage to the periphery. It is known that require considerable neural activity.The simple the auditory cortex will reorganize tonotopi- auditory task may not be improved signifi- cally if input is markedly reduced at certain 266 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

frequencies secondary to damage to the corre- speech perception abilities.19 Although these sponding part of the cochlea. The cortical re- findings often were used as reasons against the gion that previously responded to the frequen- implantation of deafened individuals outside cies that have been lost will shift to adjacent this ideal group, evidence continues to mount frequencies that are active and viable.5 This for the brain’s ability to adapt in response to permits the formerly deprived region of the AT later in life and following sustained periods auditory cortex to become physiologically ac- of deprivation. Labadie and coworkers20 found tive and retain its functional status. This neural significant increases in post-operative perfor- reorganization is a result of the dynamic and mance on word and sentence identification for active process of plasticity rather than passive two groups of implant patients with mean ages consequences of the lesion at the cochlear level.16 of 46.9 years and 71.5 years. No significant dif- The observations provided by clinical investi- ferences were reported relative to the medical gators of patients with bilateral sensorineural procedure itself, and it was concluded that hearing loss who wear hearing aids in only one neural plasticity continues to exist throughout ear provide information potentially related to life and that age alone should not be a criterion cortical reorganzation.17 These patients, over for implantation. Geier et al21 demonstrated a period of time, will demonstrate decreased that those implanted at a younger age and with speech recognition in the ear not amplified, a shorter term of deafness (defined as less than while the amplified ear’s speech recognition re- 60% of life with deafness) showed the best mained stable or, in some cases, improved. One speech recognition abilities 3 months post-im- might theorize that these clinical results indi- plantation; however, even adults who had been cate possible reorganization in the cortex. deaf for over 60% of their lives demonstrated The success of patients with cochlear im- significant speech recognition improvements. plants also provides some insights into neural Although the rate of improvement was slower plasticity. Cochlear implant patients have pro- for this latter group, speech perception abilities found hearing loss that in turn results in a form continued to improve with implant experience of auditory deprivation to the CANS, which following re-assessment at 6 months after im- could result in reorganization of the auditory plantation. Moreover, deaf subjects who used cortex. The implant allows stimulation of the sign language to communicate demonstrated central system, such that it may reconstitute successful cochlear implantation.22 While si- the more normal organization and activity of multaneously listening and watching sign lan- auditory cortical neurons that have assumed a guage, positron emission topography (PET) different role because of lack of auditory input. scans showed a shift from no activity in the au- Manrique et al18 demonstrated that a group of ditory cortex after short-term experience with pre-lingually deafened children implanted prior the implant to much higher levels of activity to 3 years of age surpassed the speech percep- following long-term experience.22 If the audition performance of post-lingually implanted tory areas of the brain previously deprived of peers as early as the third year of follow-up. auditory input are able to be stimulated, there They suggested that the critical period of de- is a potential for success, and the degree of velopmental plasticity extended up to 6 years success will largely depend on the length and of age; beyond 6 years of age, peripheral stimu- quality of follow-up and the habilitation pro- lation was not sufficient to overcome the de- cess. Imaging techniques, such as functional privation sustained by the CANS. Their find- magnetic resonance imaging (fMRI), positron ings reaffirm the expectation that the younger emission topography (PET) scans, and cortical the brain, the greater the capacity for plasticity. evoked potentials are gaining in popularity for A number of studies have focused on their potential role in demonstrating neural demonstrating that the younger the age at the plasticity of previously deprived systems in re- time of implantation, and the sooner the im- sponse to stimulation via cochlear implants and plantation following deafness, the better the through AT. AUDITORY TRAINING PROGRAMS FOR APD/MUSIEK ET AL 267

AUDITORY TRAINING ations beyond those used in the training para- WITH HUMANS digm, both behaviorally and physiologically (as recorded by the MMN). Tremblay et al30 con- Diagnostic central test procedures can guide cluded that behavioral changes are likely to fol- the clinician to the types of AT that are re- low neurophysiologic changes resulting from quired by the patient. A key component of any AT and that these neurophysiological mea- AT program is to measure AT training effects sures would serve to determine the efficacy of using various test procedures. Traditionally, be- AT. Jirsa32 showed an increase in the amplitude havioral speech perception tests have been used of the P300 and decrease in its latency in chil- as measures of auditory processing abilities, dren who underwent a general AT program. and as measures of treatment outcomes and ef- These changes in the P300 were not noted in a ficacy. Although these tests are crucial in the control group of children. Based on the MMN, auditory processing (AP) assessment battery, musicians were found to have superior audi- performance on these measures is affected by tory processing relative to nonmusicians while factors such as attention, motivation, and learn- listening to perfect versus impure chords33 and ing. Recently, attention has focused on audi- to have a more precise and longer temporal tory evoked potentials as noninvasive and more window of integration.34 These studies provide objective tools to measure auditory processing evidence that improvement in higher auditory and plasticity.23–31 Functional imaging tech- function can result from AT, this improvement niques also are being used to examine physio- can be measured with current assessment tools, logic changes of the CANS subsequent to AT. and evoked potentials can be used to differ- These tools provide an objective means to dif- entiate a range of auditory abilities in normal ferentiate subjects with known APD from listeners. normal subjects. In addition, these objective measures are increasingly demonstrating physiological changes as a result of behavioral AT FORMAL AUDITORY TRAINING in normal subjects and those with particular deficits. Typically, the process of diagnosing and man- Auditory evoked potentials are used to as- aging APD begins with parental or school sess auditory function from the periphery to concerns that result in a child being referred to the cortex through the use of electrophysio- an audiologist for AP testing. Often the con- logic responses. There are primarily two types cerns involve language, learning, reading, and of cortical evoked potentials—obligatory and auditory memory rather than, or in addition to, discriminative.24 Obligatory potentials are typ- APD. Due to the complexity and interdepen- ically elicited by clicks, tone bursts, and speech dence of these processes, it is essential that phonemes that may vary in duration. These children referred for AP testing also be evalu- cortical potentials (e.g., auditory brainstem re- ated by a speech-language pathologist and ed- sponse [ABR] and middle latency response ucational psychologist, and that the informa- [MLR]) are used clinically in auditory process- tion from these professionals be incorporated ing assessment. Discriminative evoked poten- in the management of these children. A recent tials use an oddball paradigm and are elicited consensus report provides a good reference for passively (e.g., mismatch negativity [MMN]), identification and differential diagnosis of APD, or are elicited with an active paradigm (e.g., and recommends a minimal test battery for this P300). purpose.35 Using the MMN, Kraus et al23 showed Formal AT requires the use of special in- that physiologic changes in central auditory strumentation to manipulate auditory stimuli function and auditory discrimination could be and would typically be conducted by an audiol- improved with training. Tremblay et al28 dem- ogist in the clinic or laboratory setting.36 For- onstrated that AT generalizes to listening situ- mal AT usually incorporates an intensive train- 268 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

ing schedule and targets specific stimuli using and electrophysiologic tests have concluded adaptive techniques to foster improved process- that temporal processing deficits underlie poor ing in a graded manner. The use of commercially reading skills.40 Using fMRI, Temple et al41 available computer software can complement demonstrated a lack of differential activity in formal training at school or at home when reg- the left prefrontal region of the cortex for ular visits to the lab or clinic are not feasible. rapidly and slowly changing acoustic stimuli in Because plasticity in response to AT is adults with dyslexia. Improvement in differen- highly correlated with behavioral contexts such tial sensitivity was identified in this area both as motivation,37 it is particularly important with for normal adult subjects and dyslexic subjects children to use feedback and reinforcement to following intensive training. Also using fMRI, maintain a high level of motivation during for- Temple et al42 demonstrated physiologic deficits mal AT.These considerations have been incor- for both phonologic and orthographic processes porated in commercial software supporting in children with dyslexia. AT, but they need to be addressed in any AT New training techniques have developed program, especially in training in the clinic or in parallel with the increased study of electro- lab. Modifying stimuli to maintain a fair de- physiologic measures sensitive to temporal pro- gree of success while challenging the listener cessing deficits. Merzenich et al43 demonstrated also needs to be an integral part of formal AT. the efficacy of computer games in training tem- Various types of training have shown that if poral processing thresholds of both speech and the task is too easy or too difficult, optimal nonspeech stimuli for children 5 to 10 years of changes will not result.1 It is important, there- age. This study included two-tone ordering and fore, that task difficulty be carefully selected sequencing of consonant-vowel syllables (CVs) if adaptive approaches are not employed (and modified by duration and intensity of conso- sometimes even when adaptive approaches are nants and duration of interstimulus intervals. used!). Training was intensive (20 days), tasks incorpo- A variety of formal AT techniques are rated various forms of feedback, and reinforce- outlined below. The reader is referred to Cher- ment was used as the basis for the development mak and Musiek (see pages 297–308, this issue) of currently available commercial software (i.e., for an additional discussion of formal and in- Fast ForWord [FFW]; Scientific Learning Cor- formal AT tasks, as well as general principles poration, 1997). Tallal et al44 reported that for- underlying AT. mal AT using these specially designed computer games incorporating modified temporal speech cues and enhanced speech transitions improved Temporal Processing speech discrimination and language comprehension among language-impaired children follow- There is a significant body of evidence that ing an intensive 4-week therapy program. suggests that temporal processing abilities are Several recent studies have examined the the foundation of auditory processing, specifi- efficacy of FFW.45–48 In general, these studies cally with respect to speech perception. Much demonstrate some advantages to the FFW pro- debate, however, concerns the role of temporal gram, but overall, they question its efficacy. auditory processing in children’s language and There is concern about the types of problems reading problems.38,39 Considerable research and types of populations that may be best suited has concluded that poor temporal processing for FFW. It is interesting that the more recent skills, measured behaviorally, are found in many studies do not demonstrate the same overall cases of dyslexia.38,39 Unresolved were ques- value of FFW that was shown in the original tions regarding the role of temporal processing studies.44 However, earlier and more recent for speech versus nonspeech signals and the FFW efficacy studies did not use the same eval- primacy of auditory versus visual processing uative procedures. It also is curious that none of deficits for language and reading problems. the studies employed commonly used central Recently, studies incorporating brain imaging auditory tests to measure the effects of FFW. AUDITORY TRAINING PROGRAMS FOR APD/MUSIEK ET AL 269

Kujala et al49 demonstrated—through both In light of the work by Kujala et al,50 the bi- behavioral and physiologic (MMN) measures— modal element of the Simon game could prove that a more general temporal processing deficit, to be quite beneficial. rather than a primarily linguistic deficit, is seen in dyslexic adults. Dyslexic subjects had difficulty discriminating temporal sound features Auditory Discrimination of tonal stimuli.49 Kujala et al50 also published the results of a unique, auditory-visual discrim- Auditory discrimination is one of the most fun- ination training procedure for first-graders iden- damental auditory processes. Discrimination of tified as having dyslexia. A computer game was frequency, intensity, and duration of tonal stim- developed to graphically represent the frequency, uli can be critical to the discrimination of more duration, and intensity of sound as represented complex acoustic stimuli such as speech seg- by the relative height, length, and thickness of ments and or phonemes. Studies of adult owl rectangles. One task was to identify which of monkeys showed improved frequency discrimi- the two displayed visual patterns matched the nation after systematic training, and physiologic subsequent sound pattern. The second task was and anatomic changes that correlated to the fre- to initially look at a visual pattern while listen- quencies trained, versus those that were not.11 ing to the sound pattern and identify when the More specifically, this study showed an increase last element was heard. Correct responses were in neural substrate (expanding into adjacent rewarded and incorrect responses were fol- neural areas) related to the frequencies involved lowed by a repeated presentation of the pat- in the AT. Improved performance on both be- tern. Rectangles changed colors as they were havioral tasks and increased amplitude of both presented in order to help the child track the N1 and MMN have been reported53 after train- pattern. Following auditory-visual discrimina- ing on auditory discrimination tasks. Tremblay tion training, children showed improved read- et al30 demonstrated that as voice-onset-time ing skills, as evidenced through correct identi- discrimination improved, the amplitude of the fication of words and reading speed, as well as N1-P2 late potential waveform also increased. physiologic changes (as measured by the MMN). They attributed these changes to an increased They also reported a high correlation between number of neural connections and neural syn- the behavioral and physiologic measures. It is chrony as a result of AT. Naatanen et al54 important to point out that the Kujala et al50 demonstrated a gradual sharpening or improved study used sound and visual patterns for train- discrimination following AT in normal adult ing that required temporal sequencing and cross- subjects that involved simply repeated presen- modality correlations. tations for comparisons of various complex Several studies of commercially available sounds. The comparison of complex sounds was programs suggest that through the use of intense set up in an oddball type paradigm to generate AT, temporal integration abilities improve sig- an MMN response. Although not initially pres- nificantly.51 Several informal AT techniques—as ent, the MMN was elicited later in the training. those reviewed in Musiek et al36 and Musiek25— Kraus et al23 demonstrated significant physio- also are beneficial for strengthening temporal logical changes, measured by MMN, in normal processing skills. Identifying or mimicking pat- adult subjects following speech discrimination terns with differing durations or frequencies, and training to differentiate the CV /da/ with alter- attention to stress and prosody while reading or ation of the onset frequencies of the second and listening to poetry are examples of informal AT third formant transitions. tasks that can be used to strengthen temporal Formal auditory discrimination training processing. Similarly, sequencing tones with the strategies include improving difference limens use of the commercial game Simon™ strength- (DLs) for nonspeech stimuli. This type of AT ens frequency discrimination as well as sequenc- becomes most important when abnormally large ing. The Simon game also provides a visual cor- DLs are noted for frequency, intensity, or dura- relate to the acoustic patterns used in the game. tion in children with APD. Sloan55 provides 270 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

practical ideas for training the discrimination egy when confronting an unfamiliar or misper- of speech stimuli necessary for good vowel and ceived word. As a pre-learning technique, tar- consonant identification, particularly in young get words can be chosen by school personnel or children. It is well accepted that vowel and con- parents who can identify new words for up- sonant identification and discrimination are crit- coming lessons. This allows the child to focus ical to reading and language skills. attention on the lesson itself and may foster Earobics (available from Cognitive Con- self-confidence, which may improve the likeli- cepts, Inc.) is a relatively inexpensive computer hood of class participation. This procedure in- program that has versions available for home corporates multiple processes, such as auditory, and school situations, and is easily integrated visual, and cognitive skills for word learning, into most AT programs. This program trains rather than mere memorization of vocabulary phonemic segmentation and auditory discrimi- lists. nation of vowels, consonants, and blends. It also A recent article outlines specific parameters addresses such skills as auditory memory, at- for conducting this contextual approach to vo- tention, and listening in low redundancy situa- cabulary building and includes results of a small tions. Like FFW, Earobics uses adaptive tech- survey of school personnel following use of the niques, but unlike FFW, Earobics does not contextual word derivation approach.37 Eleven emphasize temporal processing skills. In an in- of 12 respondents favored the use of this vocab- depth study of the effects of 4 weeks of Earobics ulary building program and noted improvement training for children with APD, Wheadon56 in several broad areas, such as word knowledge, reported a significant training effect on the fre- reading, and academics in general.37 quency pattern test and the Test of Auditory Comprehension of Language (TACL); there were no changes seen on dichotic digits, duration patterns, or MLR. Despite the absence of Binaural Integration and improvement on some central auditory tests, Binaural Separation the author concluded that Earobics training was of benefit to children with APD enrolled Binaural integration and binaural separation in this study. tasks are warranted when deficits are identified during dichotic evaluations. A common finding in children with APD is a left ear deficit on Auditory Closure dichotic speech tasks. Musiek and Shochat demonstrated significant improvement in bin- Children identified with poor auditory closure aural listening when dichotic training tasks skills, with language and learning disabilities, were incorporated in AT.58 Before training, the and those with poor speech perception can po- listener demonstrated a unilateral deficit on di- tentially benefit from a vocabulary building chotic digits tests and moderate, bilateral deficits technique based on Miller and Gildea’s research on compressed speech with reverberation tests. of how children learn words.57 In this proce- Training involved directing the stimuli to the dure, the child is exposed to unknown words stronger ear at a reduced level, while maintain- through reading, listening, and pronouncing ing the higher intensity level to the weaker ear. the new words. The new words are then placed This paradigm maintains good performance in context and the child is required to use this levels in the weaker ear as the intensity level of context to deduce the meaning of the word the stronger ear is gradually raised over a pe- (i.e., contextual derivation). It is important that riod of time. This procedure can also be modi- the context has a sufficient number of contex- fied by using temporal offsets that lag in the tual cues so the child can successfully derive poorer ear, which improves the poorer ear’s per- the meaning of the unknown word. Improved formance. By using adaptive techniques, the use of contextual cues and a larger vocabulary offset differentials are reduced over multiple base can serve as a useful compensatory strat- practice sessions. This allows the improved per- AUDITORY TRAINING PROGRAMS FOR APD/MUSIEK ET AL 271 formance of the good ear to stabilize back to poor auditory memory. Auditory memory is normal and maintain the improvement of the involved in a number of tasks employed in weak ear at a higher level of performance. AP testing, including frequency and duration Dichotic listening training can support patterns tests, dichotic digits, and competing both binaural integration and binaural separa- word tests (e.g., the Staggered Spondaic Word tion. The integration task requires the patient Test [SSW]).62 For this reason, AME has been to respond to the stimuli in both ears. In the recommended when deficits are found across separation task, the patient is usually asked to the AP test battery, across multiple academic ignore one ear and respond to stimuli presented subjects, or whenever auditory memory is a in the other. Dichotic training should employ a concern. wide variety of dichotic stimuli such as words, Based on psychologic research for enhanc- CVs, numbers, phrases, sentences, and coming recall, AME has been modified for use plex acoustic stimuli. Other modifications of with the APD population.52 The procedure in- binaural integration and separation procedures volves having the child read aloud or having can enhance training.59 In a study on the train- the adult read to the child, a paragraph or longer ing of dichotic listening similar to that just passage that constitutes a segment. A segment mentioned,60 improvements were shown in di- is defined as the context that conveys a main chotic listening abilities for a group of children idea. The child’s tasks following the reading of with learning disabilities and dichotic deficits a segment are to distill the segment into the compared to a control group. main idea and to sketch the main idea on paper. The process is repeated for each segment until the end of the passage. When the child has Auditory Vigilance completed all the sketches for each of the defined segments, he/she is required to review all Auditory vigilance is essentially the ability for the sketches and verbally relate the concepts a listener to remain attentive to auditory stim- underlying the segments. The goal of AME is ulation over a sustained period of time. Audi- to develop the child’s ability to listen for gen- tory vigilance underlies listening and learning eral concepts rather than trying to hear, pro- in the classroom, influences APD diagnostic cess, and recall large amounts of detail. A time test outcomes, and indeed influences AT itself, limit of one minute for each sketch is recom- as all require the listener to actively focus on mended. This forces the child to reduce infor- auditory stimuli for extended periods of time. mation by transferring it for Gestalt process- It is hypothesized that sustained, increased ing. This helps the child formulate concepts awareness to acoustic stimuli will improve au- and readies the information for easy memory ditory vigilance. Informal AT techniques in- integration. Sketching assists memory through clude the use of complex or multi-step audi- visual, spatial and motor (multisensory) repre- tory directives requiring that the child first sentations, that also increase the number of listen to instructions in their entirety before neural circuits available to memory areas.52 performing a task.36 Providing target words, Though based on well-founded concepts re- sounds, categories or ideas randomly scattered lated to memory, the AME still awaits further throughout increasingly longer passages that evaluation. are read to the child, provides a simple means of training this ability. SUMMARY AND CLOSING COMMENTS Auditory Memory Enhancement (AME) The link between successful AT and plasticity As indicated by frequent concerns from par- is a critical one. AT for individuals with APD ents, school personnel, and educational psy- will benefit from increased understanding of chologists, children with APD often display neural plasticity. As discussed in this article, 272 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

there is evidence that the brain can reorganize ing attacks a common dichotic listening deficit relatively quickly when it is deprived of acous- observed in children with APD—asymmetrical tic input. This reorganization is an important ear performance. The auditory memory en- form of neural plasticity. Questions remain as hancement procedure (AME) is a simple ther- to whether this plasticity evolves so that the apy that incorporates some complex processes neural substrate can remain physiologically vi- that should benefit memory and, therefore, sup- able or to accommodate changing demands on port auditory processing. The AME procedure the system. Neural plasticity is demonstrated involves multi-modality representations, orga- when the auditory system is trained and im- nizational perspective and concept formulation; proves in its function. Whether plasticity evolves therefore, it also should have a positive influ- because there are neurons held in reserve for ence on academic performance. just these purposes or because synaptic endings In closing, we would like to mention two are growing and making new connections also aspects of AT that have only been alluded to in remains to be clarified. These are some critical this article but are critical to success—attention questions that science is on the verge of an- and motivation. Though attention and motiva- swering. Clinicians involved in treating and tion are not considered part of mainstream au- managing APD should continue to follow ad- ditory processing or AT, they are factors that vances in brain plasticity in order to best select influence outcomes and must, therefore, be ad- and modify training programs for their patients. dressed by clinicians. Therapies will only work A number of AT techniques are emerging, if the patient is willing to put forth effort. Ef- especially in the area of temporal processing. fort requires motivation and attention, and ef- Probably the best known is the FFW program. fort is key to triggering plasticity.Though many Reports of the efficacy of FFW are mixed. The computer programs have attractive animations initial research report by Tallal et al44 was im- to keep the child captivated and working, noth- pressive; however, more recent reports have ing will replace the many advantages of a car- raised questions about the outcomes.45–48 The ing, supportive and innovative therapist in cre- discrepancies in outcomes may be related to ating high motivation and sustained attention the selection of patients. The current patient during therapy. In the days when new instru- base may be broader than the base in earlier mentation and computer software are rapidly studies. Some patients may be better suited becoming a dominant part of our habilitative than others to use and benefit from FFW. Ad- approach, we must understand that the thera- ditional research is needed to determine which pist remains the critical link to success. auditory processing deficits are best trained through this procedure. Clinicians also should consider the variety of temporal processing ABBREVIATIONS training procedures that can be employed in a more informal or formal manner to treat par- ABR auditory brainstem response ticular deficits. In addition, clinicians should AME auditory memory enhancement consider the use of other commercial programs AP auditory processing that focus on auditory-language (e.g., phone- APD auditory processing disorders mic awareness training) (e.g., Earobics™, Cog- AT auditory training nitive Concepts, Inc., Evanston, IL). These CANS central auditory nervous system programs may be more applicable to a broader CVs consonant-vowel syllables range of auditory-language deficits. Though DL difference limen some studies indicate Earobics to have thera- FFW Fast ForWord peutic value,56 more research needs to be done. fMRI functional magnetic resonance imaging One of the therapies that is rather intrigu- MLR middle latency response ing and for which some important mechanisms MMN mismatch negativity potential are known is dichotic listening therapy. This PET positron emission topography adaptive technique of training binaural listen- SC superior colliculus AUDITORY TRAINING PROGRAMS FOR APD/MUSIEK ET AL 273

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Plasticity, Auditory Training, and Auditory Processing Disorders

Frank E. Musiek, Ph.D.,1 Jennifer Shinn, M.S.,2 and Christine Hare, M.A.1

ABSTRACT

KEYWORDS: Auditory processing disorder, auditory training, plasticity

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Frank E. Musiek, Ph.D., Department of Communication Sciences and Otolaryngology, School of Medicine, University of Connecticut, Storrs, CT 06269. E-mail: [email protected]. 1Department of Communication Sciences and Otolaryngology, School of Medicine, University of Connecticut, Storrs, Connecticut; 2Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,263,276,ftx,en;sih00220x. 263 264 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Auditory Processing Disorders: Management Approaches Past to Present

Diane Wertz, M.S.,1 James W. Hall III, Ph.D.,1 and Wes Davis II, Au.D.1

ABSTRACT

The ultimate goal of screening and diagnostic assessment for auditory processing disorder (APD) is to determine an effective management strategy.The effectiveness and precision of treatment for APD is directly related to the specificity and accuracy of the diagnosis. Historically, confusion and vagueness in the definition and diagnosis of APD was associated with scattered management approaches with unproven or, at best, questionable therapeutic value. Although embraced by some audiologists and speech- language pathologists, the outcome of these often broad-based and rather generic management methods was not supported by any evidence. In this article, we review the evolution of APD management from the two distinct professional perspectives of audiology and speech-language pathology. Linkages between current treatment options and earlier management techniques are emphasized. The goal of this brief review is to provide the reader with a better understanding of the precursors to diverse conventional and computer-mediated therapeutic techniques that are now available.

KEYWORDS: Auditory processing disorder, history, management

Learning Outcomes: After reading this article, the reader will be able to (1) discuss the origins of audiologist involvement in the assessment and management of APD; (2) differentiate the approaches to APD assessment and management taken by audiologists versus speech pathologists; and (3) identify, based on a historical perspective, the major advantages of deficit specific treatment approaches for APD.

Interest in the assessment and manage- (Fig. 1) stressed the importance of clinically ment of APD can be traced to the very begin- evaluating central auditory function, especially ning of audiology as a profession. In his text- in children suspected of communicative disor- book Auditory Disorders in Children: A Manual ders.1 Dr. Myklebust developed an international for Differential Diagnosis, Helmer Myklebust reputation in special education and learning

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: James W. Hall III, Ph.D., Department of Communicative Disorders, P.O. Box 100174, 1600 Archer Road D2–13, University of Florida, Gainesville, FL 32610–0174. Email. [email protected]. 1Department of Communicative Disorders, College of Health Professions, University of Florida, Gainesville, Florida. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,277,286,ftx,en;sih00221x. 277 278 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

found in the audiology textbooks of the day. For example, in his popular book, Audiology (4th edi- tion), Hayes Newby4 provided a very modest discussion of central auditory disorders, emphasizing neuropathologies such as brain tumors and abcesses, vascular insults, traumatic brain injury, infections (e.g., meningitis and encephali- tis), degenerative diseases (e.g., Parkinson’s disease or multiple sclerosis), and pediatric central nervous system disorders (e.g., erythroblastosis fetalis, kernicterus). In an apparent reference to what we would now refer to as APD, Newby used the term auditory imperception and noted that “children of normal intelligence and normal hearing sensitivity who do not develop language abilities at the usual time are frequently des- ignated aphasic.” Following a brief review of Figure 1 Helmer Myklebust, Ph.D. A professor in the learning disabilities program at Northwestern Uni- organic brain disorders, Newby concluded with versity for many years, Dr. Myklebust was instrumen- a somewhat curious and contradictory passage: tal in raising the awareness of central auditory func- “Because it is a neurological disorder, a central tion among audiologists and speech pathologists. problem falls within the domain of the neurolo- gist, neurosurgeon, and psychiatrist, rather than disabilities. He earned an M.A. in the psychol- that of the otologist. The audiologist, however, is ogy of deafness from Gallaudet University in interested in central auditory disorders because 1935, another M.A. in clinical psychology from part of the audiologist’s responsibility is to dif- Temple University in 1942, and then an Ed.D. ferentiate peripheral from central impairments” in psychology and counseling from Rutgers (page 101). Hayes proffers no other comments University in 1945. His first position, in 1931, regarding management. In another popular text- was as an instructor at the School for the Deaf book of the time—Hearing and Deafness (3rd edi- in Knoxville, Tennessee. From 1948 to 1969, tion), Davis and Silverman5 provide a similar re- Myklebust was a professor of psychology, neu- view of organic etiologies for central dysacusis rology, and psychiatry, and Director of the and also do not venture into the topic of man- Institute for Language Disorders at North- agement by the audiologist. western University where he was a colleague of Given the paucity of formal education on Raymond Carhart (the Father of Audiology) the principles of APD assessment and man- and where he also influenced a promising young agement, and of clinical training with APD auditory scholar—James Jerger. In his writings, patient populations available to audiologists Myklebust clearly delineated the connection during this time period, it is not surprising that between the auditory modality and language. their management of patients with APD, if In addition, he admonished the clinician (i.e., considered at all, tended to be rather unin- audiologist) to go beyond an evaluation of pe- spired and generic. In fact, the responsibility ripheral auditory function in the clinical as- for treatment of children with “auditory imper- sessment of hearing in children. In the era ception” or “central dysacusis” was more com- when the audiogram reigned supreme, Mykle- monly assumed by the speech-language pathol- bust promoted true measurement of hearing ogist rather than the audiologist. (i.e., of higher level auditory processes). As early as the 1970s, one audiologist— Even with the emergence in the 1970s of Robert W. Keith (Fig. 2)—tackled the clinical test batteries for differential diagnosis of central challenge of central auditory processing disor- auditory function,2,3 management of APD was ders head on. Dr. Keith has for many years been not within the scope of practice for the typical on the faculty at the University of Cincinnati audiologist. Support for this statement can be College of Medicine. Beginning with his edited MANAGEMENT APPROACHES TO APT/WERTZ ET AL 279

In the following discussions, we review briefly the roles assumed by each professional in the management of children with APD.

THE SPEECH-LANGUAGE PATHOLOGY PERSPECTIVE

Historically, the management of APD has been as diverse as the definitions and theories that define the disorder. Professionals who approach APD can be broadly divided into two groups: those who ascribe to a language-based origin, in which deficits are viewed in terms of their linguistic dependency, and those who maintain that disorders are auditory-perceptual in nature, and occur due to a breakdown in Figure 2 Robert W. Keith, Ph.D. Dr. Keith has made the central auditory nervous system. Cognitive varied contributions to our understanding of auditory neuroscience correlates these two views as top- processing disorders. He has also developed stan- down processing or bottom-up processing. In- dardized measures of auditory processing for children and adults. tervention strategies have varied throughout the years depending on the processing model used. We review the history of APD manage- textbook Central Auditory Dysfunction,”6 Keith ment strategies that have used either or a com- exerted a significant influence on the audiologic bination of these processing models. approach to assessment of this important clini- Myklebust1 was one of the first researchers cal population. With over 50 book chapters and to state that an auditory deficit could explain journal articles, and hundreds of workshops and language disorders in children. This auditory convention presentations on APD, he single- deficit was labeled as the “auditory perceptual handedly altered clinical standard-of-care for deficit” or “auditory language learning disorder,” many practicing audiologists. He also served as and was considered a list of symptoms without a mentor for dozens of graduate students. a disease.7 The symptoms included an inability Among audiologists and speech pathologists, to use spoken or linguistic auditory input ef- Keith is well known for his published tests. His fectively. If this model were endorsed, then commercially-available clinical procedures in- presumably the symptoms caused the language clude the SCAN-C: A Screening Test for Audi- dysfunction and isolating the symptoms and tory Processing Disorders in Children (Psycho- treating them would cure the language prob- logical Corporation, 1986), SCAN-A: A Test lem. Rees,8 and Bloom and Lahey,9 among oth- for Auditory Processing Disorders in Adoles- ers, disagreed with this bottom-up language cence and Adults (Psychological Corporation, processing view. Instead, these researchers as- 1994), the Auditory Continuous Performance serted that the auditory problem was due to a Test (Psychological Corporation, 1994) for dif- language disorder, a top-down language pro- ferentiation of attention deficit disorder, the cessing view. Therefore, management was con- Auditory Fusion Test Revised (Auditec of St. centrated on training language skills, rather Louis, 1996), the Random Gap Detection Test than isolated auditory functions. The goals of (Auditec of St. Louis, 2000), and the Time this language intervention were formulated in Compressed Sentence Test (Auditec of St. terms of language use: the sounds, words, sen- Louis, 2002). We are indebted to Dr. Keith for tences, and communicative function that the his innumerable contributions to the profession child needed to employ to function more suc- of audiology and, in particular, to our under- cessfully in his or her environment. Speech- standing of auditory processing disorders. language pathologists made the distinction 280 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

between auditory perception and auditory com- along with other researchers, suggested that an prehension, and asked the question: are the auditory processing deficit underlies certain children misperceiving what they hear or fail- speech and language disorders in children. ing to understand what they perceive? That is, difficulties in auditory processing led to difficulties in auditory perception, and subsequently in impaired language development. Top-Down Management Approaches Sloan12 defined auditory processing difficulty as the difficulty in processing the acoustic sig- In 1971, Patricia and Phyllis Lindamood10 de- nal that interferes with accurate and efficient veloped the multisensory Auditory Discrimi- perception of speech. She developed a treat- nation in Depth (ADD) Program (now called ment program that was based on an integration LIPS) based on research that stressed the im- of theory, research, and clinical experience. The portance of auditory perception and compar- Sloan program was designed to facilitate more ing phonemes in spoken syllables (or, as it was accurate and efficient speech perception by termed by the Lindamoods, auditory concep- training speech discrimination. The child learns tual function), and its relationship to speech, to discriminate speech-sound contrasts in in- reading, and spelling. Samuel Orton,11 a neu- creasingly more difficult phonetic sequences. rologist, first described this important rela- In noting that her program was not intended tionship in 1937. The Lindamoods explained to address all aspects of auditory processing auditory processing as five general processes: difficulties, Sloan suggested additional therapy sensory input, perception, conceptualization, to develop better use of contextual cues in au- storage, and retrieval. According to the Lin- ditory perception and comprehension.12 damoods, if sensory input is incomplete, then any other process can encounter difficulty. The LIPS program is based on a multisensory ex- Combined Top-Down/Bottom-Up perience. The speech sounds are taught based Management Approach on their individual characteristics that can be heard, seen, and felt through oral-motor activi- In 1992, the American Speech-Language ties. A questioning process is used that helps Hearing Association13 issued a definition of the student discover the sensory feedback from central auditory processing disorders (CAPD): ear, eye, and mouth involved in identifying, “CAPD refers to limitations in the ongoing classifying, and labeling the speech sounds. transmission, analysis, organization, transfor- Orton and Anna Gillingham also devel- mation, elaboration, storage, retrieval, and use oped a multisensory reading instruction program of information contained in audible signals.” that was language based. The Orton-Gilling- Expanding on this approach, Dorothy Kelly14 ham program is a structured, sequential, and described central auditory processing as a phe- cumulative program, similar to LIPS. How- nomenon involving a range of behaviors from ever, the kinesthetic portion of the remediation awareness of the presence of sound to higher- was tactile, having the child write letters and order analysis of linguistic information. Kelly words with their finger rather than having the developed management strategies that blended source of sensory information come from the both bottom-up and top-down processing, oral-motor activity that produces them, as in concentrating on auditory memory, auditory the LIPS program. discrimination, auditory figure-ground, auditory cohesion, and auditory attention.14 In 1996, the ASHA Task Force on Central Audi- Bottom-Up Management Approaches tory Processing developed a much more concise definition of CAPD, due to improved diagnos- A bottom-up, auditory perceptual approach tic testing. CAPD was defined as a deficiency to management was developed by Christine in one or more of the central auditory pro- Sloan.12 Sloan stated that auditory perception cesses. A year later, ASHA published guide- was the outcome of auditory processing. She, lines for APD management.15 MANAGEMENT APPROACHES TO APT/WERTZ ET AL 281

THE AUDIOLOGY PERSPECTIVE dren with hearing loss.16,19 Certainly, one can assume that children with APD also may expe- Even in the 1990s, most audiologists did not in- rience difficulties with noise. Examples of corporate assessment and management of APD sources of noise in a typical classroom may in- into their clinical practice. Based on the content clude other children talking, shuffling papers, of popular audiology textbooks, the relatively chair/desk legs sliding on a floor, air condition- few who performed screening and audiologic as- ing units, and so on. Children may experience sessment of children with suspected APD were the aforementioned detrimental effects of noise encouraged to employ general and one-size- on speech perception in a variety of ways, in- fits-all strategies for the management of chil- cluding upward spread of masking, attention dren. The two most common management ap- problems, and/or concentration.16 proaches, and the strategies that remain the most Assessment of the child’s individual edu- readily embraced by the audiologist, are modifi- cational situation may reveal specific opportu- cations of the classroom and the recommenda- nities for noise reduction and SNR improve- tion for some type of assistive listening device. ment, such as preferential seating away from For children with APD, classroom envi- noise generators (e.g., air conditioners) or plac- ronmental modifications are crucial. The accu- ing tennis balls on the bottoms of metal chair rate perception of speech is perhaps the most legs, etc. However, excessive reverberation and vital factor in a child’s academic success or fail- noise in many classrooms may make acoustic ure in the classroom.16 Therefore, classroom modification of the room (that meets acoustic acoustics are a key variable in academic achieve- standards) prohibitively expensive. In such cases, ment. Children with APD often experience frequency-modulated (FM) systems may be compromised ability to perform auditory clo- the best consideration.19 FM systems attempt sure tasks (such as speech-in-noise tasks) and to reconcile two separate classroom acoustics may therefore benefit from an improved signal- problems. FM systems enhance the SNR by to-noise ratio (SNR).17 For some children with increasing the teacher’s voice intensity com- APD, classroom acoustic modification is no pared to the rest of the classroom. Addition- doubt an element in ensuring academic success. ally, FM systems effectively decrease speaker- One important aspect of the classroom to-listener distance, which can improve speech environment is reverberation. Reverberation is perception. These improvements can affect the prolongation of sound waves from a sound the student’s ability to adequately understand source as they reflect off of hard surfaces in a the teacher and thus improve academic perfor- room. Reverberation can detrimentally affect a mance. FM systems are available as personal child’s ability to understand a spoken message FM systems (with headphone or earbud use, a and consequently can hinder his/her academic small desktop speaker, or via direct input into a progress.16 Generally, the larger the classroom, hearing aid), and sound-field systems. Histori- the greater the reverberation problems. Addi- cally, clinicians believed that FM systems would tionally, classrooms with hard surfaces and benefit all children diagnosed with APD. How- bare walls, floors, and ceilings tend to exhibit ever, as diagnostic assessment has improved, higher reverberation times (i.e., poorer acous- FM systems are not recommended for every tic properties). Reverberation time can be de- child with APD,20 but rather for those children creased by using smaller classrooms and by that have difficulty understanding speech in using absorptive surfaces (e.g., carpeting, drap- the presence of competing noise. The reader is ery, acoustic ceiling tiles). referred to the articles by Ferre, and by Rosen- Another major problem many children berg (this issue, pages 319–326, and pages face in today’s educational setting is general 309–318, respectively) for a further discussion classroom noise. Noise may be defined as any of this topic. undesired auditory disturbance that interferes Classroom acoustic modification, whether with what the listener intends to hear.18 Noise by environment modification, preferential seat- can compromise speech perception abilities in ing, or FM system use, remains an important children with normal hearing as well as in chil- consideration for APD treatment in the aca- 282 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

demic setting. FM systems are a cost effective often a neuropsychologist, occupational thera- way to effectively increase the SNR of the pist, and other health care professionals.22,23 teacher’s voice while decreasing speaker-to- The importance of an individualized manage- listener distance.19 As previously discussed, audi- ment plan for each child is now stressed. Indi- ologists have viewed classroom amplification as vidualized plans that include modifications a simple, relatively cost effective strategy for en- (i.e., changes in what a child is expected to learn hancing the chances of academic success, espe- and demonstrate) and accommodations (i.e., cially for children with APD. For these reasons, provisions made in how a student accesses and classroom acoustics modification deservedly has demonstrates learning) for the child with APD continued to be a viable option for the audiolo- have become easier to obtain in the school set- gist in managing the child with APD. ting with the passing of the Individuals with Jack Katz, widely acknowledged as an ex- Disabilities Education Act (IDEA), the Ameri- pert on APD, summarized the foregoing generic cans with Disabilities Act (ADA) and the Sec- management approach for children identified tion 504 of the Rehabilitation Act. Children with APD 21. He identified four specific compo- with APD who are not eligible under IDEA, nents for management of APD in the school: may still be eligible for modifications and accommodations under Section 504 and ADA. • classroom instruction adaptations (e.g., writ- Examples of accommodations that have been ten information to supplement verbal infor- recommended for children with APD include mation), the use of a note-taker, visual supplements, study • classroom acoustic modifications to reduce guides and pre-teaching, peer partners, ad- noise, justed pace of instruction, repetition of ideas, • assistive listening devices (classroom and in- and reduced language level. Examples of mod- dividual FM), ifications that have been recommended for • unilateral earplugs (to minimize the deleteri- children with APD include reducing the diffi- ous effect of the weak ear in dichotic tasks) culty of the material, shortening assignments, or bilateral earplugs (to minimize the dis- giving alternative assignments, and using an traction of background noise). alternative grading system. See the article by Ferre (this issue, pages 319–326) for a discus- Suggesting a shift in the traditional audio- sion of this topic. logic management approach, Katz went on to In 1997, Chermak and Musiek24 devel- note that “recommendations should be based oped a comprehensive management approach on the individual’s needs and the problem situ- to APD to address the range of listening and ations faced, rather than simply a generic ap- learning deficits experienced by children with proach.”21 He then cited specific examples of APD (Table 1). The intervention was a combi- individual and direct therapy techniques to im- nation of auditory training, and metalinguistic prove phonemic concepts and skills, desensiti- and metacognitive strategies designed to in- zation to background noise, and development crease the scope and use of auditory and cen- of auditory memory and sequencing abilities. tral resources. The auditory training portion Recently, the trend in APD management has focused on detection, discrimination, vigilance, been toward more individualized, prescriptive, binaural listening, and interhemispheric trans- and evidence-based therapy. fer. The metalinguistic strategies focused on discourse cohesion devices, vocabulary building, segmentation and auditory discrimination, and prosody. The metacognitive strategies focused RECENT DEVELOPMENTS on understanding task demands, appropriately allocating attention, identifying important parts With time, management of APD has taken on of a message, self-monitoring, self-question- a multidisciplinary approach. The management ing, and deployment of debugging strategies. team now must include an audiologist, a speech- The proliferation of the affordable personal language pathologist, teachers, and parents, and computer during the last two decades has per- MANAGEMENT APPROACHES TO APT/WERTZ ET AL 283

Table 1 Strategies and Techniques for Management of Auditory Processing Disorders Functional Deficit Strategies Techniques

Distractibility/inattention Increase signal-to-noise ALD/FM system; acoustic modifications; ratio preferential seating Poor memory Metalanguage Chunking, verbal chaining, mnemonics, rehearsal, paraphrasing, summarizing Right hemisphere activation Imagery, drawing External aids Notebooks, calendars Restricted vocabulary Improve closure Contextual derivation of word meaning Cognitive inflexibility Diversify cognitive style Top-down (deductive) and bottom-up (predominantly analytic (inductive) processing, inferential reasoning, or predominantly questioning, critical thinking conceptual) Poor listening Induce formal schema to Recognize and explain connectives comprehension aid organization, integration, (additives; causal; adversative; temporal) and prediction and patterns of parallelism and correlative pairs (not only/but also; neither/nor) Maximize visual and Substitutions for notetaking auditory summation Reading, spelling, and Enhance multisensory Phonemic analysis and segmentation listening problems integration Maladaptive behaviors Assertiveness and cognitive Self-control, self-monitoring, self-evaluation, (passive, hyperactive, behavior modification self-instruction, problem solving impulsive) Poor motivation Attribution retraining, internal Failure confrontation, attribution locus of control to factors under control

Adapted from Chermak and Musiek,30 with permission. mitted a new strategy for APD management. pitch pattern, temporal processing, working Computer software programs are now available memory, as well as reading and language skills. and no doubt more will be developed that offer Similarly, Earobics provides several software a variety of APD-specific therapies. While options for patients of different skill levels and many habilitation techniques developed prior to ages. Earobics programs engage the child in a the widespread availability of computers have variety of activities from phonologic awareness involved frequent and often intensive patient- to language comprehension. The two programs therapist interaction, computer programs offer mentioned are by no means the only software the audiologist a different treatment option. Be- packages available, but at the time of this publi- cause many families own computers, software cation they do garner a great deal of market at- programs can be used in the home setting with- tention. See also the articles by Musiek, Shinn out the need for direct specialist supervision. In- and Hare, and by Phillips (this issue, pages deed, most software programs currently avail- 263–276, and pages 251–263, respectively). able offer products directly to the consumer. Earobics™ (Cognitive Concepts, Evanston, IL25) and Fast ForWord™ (Scientific Learning, Berkley, CA26) are two such computer-based CONCLUSIONS software patient-interaction programs. Fast ForWord provides a variety of software pack- In reviewing the history of the management of ages for different patient populations, addressing APD in children, the paucity of empirical data several auditory-related components including regarding efficacy becomes obvious. Demon- 284 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

strating treatment efficacy requires document- REFERENCES ing that an important change occurred in a child’s performance due to the treatment rather 1. Myklebust HR. Auditory Disorders in Children: A than from maturation or some uncontrolled or Manual for Differential Diagnosis. New York: Grune & Stratton; 1954 unknown factor. Efficacy of treatment in APD 2. Jerger J, Jerger S. Clinical validity of central audi- should be a high priority for future research. tory tests. Scand Audiol 1975;4:147–163 Indeed, the report of the 2000 Consensus 3. Williford JA, Bilger JM. Auditory perception with Conference on APDs in Children27 identified learning disabilities. In: Katz J, ed. Handbook of among future research needs: Clinical Audiology, 2nd ed. Baltimore, MD: Williams & Wilkins; 1978:410–425 4. Newby HA. Audiology, 4th ed. Englewood Cliffs, • the relationship between APD test outcomes NJ: Prentice-Hall; 1979 and management strategies, 5. Davis H, Silverman SR. Hearing and Deafness, 3rd • outcomes of early intervention for APD, ed. New York: Holt, Rinehart and Winston; 1970 6. Keith RW, ed. Central Auditory Dysfunction. • the relative efficacy of intervention approaches New York: Grune and Stratton; 1977 at various ages (p. 472). 7. Northern J, Downs M. Hearing in Children. Balti- more, MD: Williams & Wilkins; 1991 8. Rees NS. Auditory processing factors in language Some have questioned the 2000 Con- disorders: the view from Procruste’s bed. J Speech sensus Conference’s emphasis on differential Hear Disord 1973;38:304–315 diagnosis of APD. Katz et al28 stated: “the audi- 9. Bloom L, Lahey M. Language Development and ologist’s most valuable role is guiding the man- Language Disorders. New York: Wiley; 1978 agement of the child with APD” and “For chil- 10. Lindamood C, Lindamood P.The Lindamood Au- dren with APD, our goal is to address their ditory Test of Conceptualization (LAC). Boston, MA: Teaching Resources Corp.; 1971 learning and communication difficulties rather 11. Orton ST. Reading, Writing, and Speech Problems than to determine if pathological/physiological in Children. New York: W.W. Norton; 1937 auditory variations are present” (page 17). While 12. Sloan C. Treating Auditory Processing Difficulties we wholeheartedly agree that audiologists must in Children. San Diego, CA: Singular; 1991 play an important role in the management of 13. American Speech-Language-Hearing Associa- APD, we also concur with Jerger and Musiek,29 tion. Issues in Central Auditory Processing Disor- who emphasized that “appropriate intervention ders: A Report from the ASHA Ad Hoc Commit- must derive from accurate diagnosis” (p. 19). tee on Central Auditory Processing. Rockville, MD: American Speech-Language-Hearing Asso- Indeed, the increased specificity in manage- ciation; 1992 ment strategies within recent years appears to 14. Kelly DA. Central Auditory Processing Disorder: be a direct outgrowth of more precise methods Strategies for Use with Children and Adoles- for description, definition, and diagnosis of cents. San Antonio, TX: Communication Skill specific auditory processes. (See the articles by Builders; 1995 Ferre and by Bellis, this issue, pages 319–326, 15. American Speech-Language-Hearing Associa- and pages 287–296, respectively). tion. Management Guidelines for Central Au- ditory Processing Disorders. Rockville, MD: American Speech-Language-Hearing Associa- tion; 1997 16. Crandell C, Smaldino J. The importance of room ABBREVIATIONS acoustics. In: Tyler RS, Schum DJ, eds. Assistive Devices for Persons with Hearing Impairment. ADA Americans with Disabilities Act Boston, MA: Allyn & Bacon; 1995 APD auditory processing disorder 17. Bellas T. Assessment and Management of Central CAPD central auditory processing disorder Auditory Processing Disorders in the Educational Setting. From Science to Practice. San Diego, CA: FM frequency-modulated Singular; 1996:128 IDEA Individuals with Disabilities Education 18. Finitzo-Heiber T. Classroom acoustics. In: Roeser Act R, Downs, eds. Auditory Disorders in School SNR signal-to-noise-ratio Children, 2nd ed. 1988:221–233 MANAGEMENT APPROACHES TO APT/WERTZ ET AL 285

19. Crandell C. Page ten: utilizing sound field FM am- 26. Scientific Learning. www.Scientificlearning.com plification in the educational setting. Hear J 1998; 1998 51:10–19 27. Jerger J, Musiek FE. Report of consensus confer- 20. Ferre J. CAP tips. Ed Audiol Rev 1999;16:28–32 ence on the diagnosis of auditory processing disor- 21. Katz J, Wilde L. Auditory processing disorders. In: ders in school-aged children. J Am Acad Audiol Katz J, ed. Handbook of Clinical Audiology, 4th ed. 2000;11:467–474 Baltimore, MD: Williams & Wilkins; 1994:490–502 28. Katz J, Johnson CD, Brandner S, et al. Clinical and 22. Hall JW III. CAPD in Y2K: an introduction to au- research concerns regarding the 2000 APD con- diologic assessment and management. Hear J 1996; sensus report and recommendations. Audiology 52:35–42 Today 2002;11:14–17 23. Hall JW III, Mueller HG III. Audiologists’ Desk 29. Jerger J, Musiek FE. On the diagnosis of audi- Reference, vol. I. San Diego, CA: Singular tory processing disorder. Audiology Today 2002; 24. Chermak G, Musiek F. Central Auditory Process- 11:19–21 ing Disorders: New Perspectives. San Diego, CA: 30. Chermak GD, Musief FE. Managing central audi- Singular; 1997 tory processing disorders in children and youth. 25. Cognitive Concepts. www.Earobics.com 1998 Am J Audiol 1992;1:61–65

Developing Deficit-Specific Intervention Plans for Individuals with Auditory Processing Disorders

Teri James Bellis, Ph.D.1

ABSTRACT

Intervention for auditory processing disorders (APD) should arise logically from the nature of the individual’s auditory deficit and how that deficit relates to functional difficulties and behavioral sequelae. Although many management and remediation techniques have been proposed for treating APD, the relative efficacy of any given approach will depend on its appropriateness to the specific APD in question. This article will address methods of customizing APD intervention based on diagnostic findings and functional deficit profiles.

KEYWORDS: Auditory processing disorders, intervention, management, environmental modifications, compensatory strategies, auditory training

Learning Outcomes: After reading this article, readers will be able to: (1) Discuss the rationale underlying deficit-specific intervention for APD, (2) Identify methods of customizing APD intervention based on functional deficit profiles, and (3) Delineate needed areas of research in deficit-specific intervention for APD.

The utility of deficit-specific intervention Auditory Processing Consensus Development,1 for auditory processing disorders (APD) is based these fundamental skills or processes include on three primary assumptions. First is the as- sound localization and lateralization, auditory sumption that certain basic auditory skills or discrimination, auditory pattern recognition, processes underlie more complex listening, temporal aspects of audition, and auditory per- learning, and communication abilities. Accord- formance with degraded and/or competing ing to the American Speech-Language-Hearing acoustic signals. As such, APD is best viewed Association (ASHA) Task Force on Central as a sensory-based input deficit in one or more

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Teri James Bellis, Ph.D., Department of Communication Disorders, University of South Dakota, 414 E. Clark Street, Vermillion, SD 57069. E-mail: [email protected]. 1Department of Communication Disorders, University of South Dakota, Vermillion, South Dakota. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,287,296,ftx,en;sih00222x. 287 288 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

of these processes that then can lead to diffi- the influence of nonauditory factors, such as culty in higher-order, more complex behaviors attention, memory, and language, on test per- such as listening, language use, and learning. formance.6–9 Finally, data to support the effi- A second assumption underlying the util- cacy of specific treatment approaches for APD ity of deficit-specific intervention for APD is are in large part lacking at the present time. that the capability exists for identifying those Notwithstanding these caveats, logic dic- auditory processes that are dysfunctional in a tates that the most efficacious approach to APD given individual through the use of diagnostic intervention would be one that arises logically tests of central auditory function. Toward this from the specific auditory deficit area(s) identi- end, Domitz and colleagues2–4 conducted a se- fied and the functional, behavioral symptoms ries of studies to investigate the relationship be- exhibited by the individual. Outcomes of diag- tween several commonly used central auditory nostic testing, combined with information from tests and the fundamental auditory processes multidisciplinary evaluations of language, learn- identified in the 1996 ASHA consensus state- ing, and cognitive function, provide a frame- ment.1 Their results indicated that no single work for guiding the intervention effort.8,10–14 test was sufficient to diagnose APD. Rather, In this manner, a management program can be the use of a combination of tests that assess developed that is appropriate for the individual, multiple auditory processes was indicated. and the inevitable wasted time that is often the A final assumption important to the utility result of using a shotgun approach to treatment of deficit-specific intervention for APD is that, can be avoided. once identified, remediation of the underlying, deficient auditory process or processes will facilitate improvement in those higher-order, more COMPONENTS OF APD complex functional ability areas with which a INTERVENTION given individual is experiencing difficulties.Thus, from a theoretical perspective, deficit-specific in- Comprehensive intervention for APD should tervention for APD follows a fundamental med- seek to remediate the underlying auditory defi- ical model in which the primary underlying cit(s) as well as improve the individual’s ability cause of the disease or disorder is identified and to function in real-world communication and then treated in a bottom-up fashion. At the same learning environments. Any management plan time, the symptoms of the disorder—or the lan- for APD should include elements of each of the guage, learning, and communication sequelae, following three primary components.10–12,14 including secondary metacognitive or metalinguistic deficits—are addressed through top-down intervention techniques. Appropriate interven- Environmental Modifications to tion for APD is dependent on the accurate iden- Improve Acoustic Clarity and tification and diagnosis of the nature of the Enhance Learning/Listening underlying deficit(s) as well as on the determination of how the deficit(s) affects the individual in Acoustic-based environmental modifications his or her daily life. can include the use of assistive listening— Readers should be cautioned that, how- either personal or soundfield—devices, archi- ever logical this approach to APD intervention tectural interventions to reduce reverberation seems, there is a paucity of empirical evidence and improve signal-to-noise ratio, and reduc- to support these assumptions. The causal link- tion or removal of mechanical or other com- age between auditory processing deficits and peting noise sources from within and outside language, learning, or communication disorders the room.15 It is universally accepted that all has been called into question by several re- listeners perform better in an environment that searchers.5–7 The sensitivity and specificity of fosters acoustic clarity and desirable signal-to- central auditory tests in current clinical use have noise ratios. However, for some individuals been criticized, in particular, for the lack of a with auditory deficits, particularly those that gold standard for validation of these tests and reduce the intrinsic redundancy and clarity of DEFICIT-SPECIFIC INTERVENTION/BELLIS 289 the acoustic signal, extrinsic redundancy and effective for those individuals who exhibit audi- acoustic clarity of the incoming message will tory memory difficulties, or who have difficulty be far more critical than it will for others. independently analyzing and solving compre- Other environmental modifications may hension problems in real-world settings. They include teacher- or speaker-based interventions. also are useful for children and adults with APD However, these modifications are not equally who, over time, have become passive listeners and beneficial to all individuals with APD. There- who feel powerless to effect any change in their fore, each environmental modification recom- listening success. For an in-depth description of mended as part of a comprehensive APD in- compensatory strategies, readers are referred to tervention plan should be examined carefully Chermak,13 and Chermak and Musiek.8 to ensure that it is appropriate for the individual in question. For additional information regarding environmental modifications, readers Direct Remediation Techniques are referred to the articles by Ferre and by Rosenberg (this issue, pages 319–326 and The purpose of direct remediation activities is to pages 309–318, respectively). maximize neuroplasticity and improve auditory performance by changing the way the brain processes auditory information.8,10–14,16 Depending Compensatory Strategies to on the specific deficit present, direct therapy may Strengthen Higher-Order Top- be targeted toward phoneme discrimination ac- Down Processing Skills tivities (and concomitant speech-to-print skills); dichotic listening training in which the inten- The presence of APD often is associated with sity levels for each ear are gradually adjusted secondary deficits in attention, memory, learn- to improve the listener’s performance in the ing, and other higher-order cognitive and re- weaker (usually left) ear; localization/lateraliza- lated areas.1,8–9,13 Deficits or weaknesses in these tion training; enhancing perception of stress, nonmodality-specific, global domains can exac- rhythm, and intonational aspects of speech; ac- erbate the impact of an APD on daily function. tivities requiring temporal resolution or integra- Any comprehensive intervention plan for APD tion; perception of acoustic patterns; or multi- should address metacognitive and metalinguis- modality interhemispheric stimulation activities, tic factors in a top-down fashion. Compensatory among others. For an update and review of strategies training is not designed to remediate auditory training techniques and neuroplasticity, the underlying disorder, but rather to strengthen readers are referred to the articles by Musiek et higher-order skills that can impact auditory al, and by Chermak and Musiek (this issue, pages functioning and to teach the individual to be- 263–276 and pages 297–308, respectively). come an active participant in his or her own listening and comprehension success.8,13–14,16 Metalinguistic strategies to benefit spoken CUSTOMIZING APD language comprehension can consist of training INTERVENTION PLANS in the rules of language, formal and informal schema induction, using context to build vocabu- When designing an individualized, deficit- lary, and a variety of other activities. These activi- specific intervention plan for APD, several ties may be most appropriate for those individu- steps are required. als with auditory deficits that affect auditory closure, or who exhibit language-based disorders that either co-exist with or arise from APD. Step One: Identifying the Metacognitive and metamemory strategies are Auditory Deficit(s) designed to enhance problem-solving skills, improve the memory trace, and encourage the lis- Programming deficit-specific intervention plans tener to take responsibility for his or her own lis- for APD requires the identification of the spe- tening success. These strategies may be most cific auditory process(es) that is dysfunctional 290 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

using diagnostic central auditory tests. Accord- taps into lateralization at the brainstem level ing to the diagnostic construct suggested by is the Masking Level Difference. Additional Schow and colleagues,2–4 measurable behavioral measures of brainstem-level binaural inter- auditory processes include: action have been designed; however, their sensitivity and clinical utility is question- • Binaural separation (BS): This is the ability able.10 Localization of sound sources relies to attend to one ear while, at the same time, on far more than just binaural interaction in ignoring a competing signal in the opposite the brainstem. Additional research is needed ear. BS can be assessed through the use of di- to determine how best to measure localiza- chotic measures that require directed report tion, lateralization, and binaural interaction. of one ear, such as the Competing Sentences • Other temporal aspects of audition: Tests of Test.17 temporal processing (other than temporal or- • Binaural integration (BI): BI also reflects au- dering mentioned previously) may include ditory performance with competing acoustic measures of temporal resolution (e.g., gap signals, and can be assessed through dichotic detection, difference threshold for duration), tests that require integration and report of temporal masking and temporal integration stimuli directed to both ears, such as the Di- or summation. Temporal processes are criti- chotic Digits Test.18 cal for a wide variety of auditory behaviors and • Auditory pattern/temporal ordering (APTO): abilities, including discrimination of speech APTO requires auditory discrimination of and nonspeech signals, perception of prosodic frequency and/or duration differences, order- elements of speech, and localization/lateral- ing or sequencing of stimuli, and specific tem- ization. Therefore, temporal processing may poral processes. In addition, depending on the be thought of as underlying all of the previ- task, APTO may require interhemispheric in- ously mentioned behavioral auditory pro- tegration if the subjects are required to verbally cesses. However, with the exception of the label nonverbal tonal patterns. Tests that assess Random Gap Detection Test,21 commercially APTO include Frequency Patterns19 and Du- available tests of temporal processing are ration Patterns.20 largely lacking at present. For a discussion of • Monaural separation/closure (MSC): MSC temporal aspects of audition, readers are re- underlies performance with degraded signals, ferred to Phillips.22 such as filtered or time-compressed speech, as well as monaural performance with ipsi- The auditory processes discussed in this lateral competing acoustic signals. section represent all six of the auditory phe- • Auditory discrimination: Auditory discrimi- nomena delineated in the ASHA 1996 state- nation, or the ability to tell when two stimuli ment of central auditory processes.1 As can be are different, may be thought of as a com- seen, some can be directly assessed at the pres- plex auditory behavioral skill that is fun- ent time, whereas others represent more com- damental to all of the previously discussed plex abilities requiring further investigation to auditory phenomena. It can be assessed in- isolate and measure. We are able currently to dependently through the use of difference identify many underlying dysfunctional pro- limens for frequency, intensity, duration, or cesses for the purpose of programming deficit- speech stimuli, as well as via speech-sound specific intervention using existing central au- and word discrimination tests, many of which ditory tests. are key components of the speech-language pathologist’s and/or audiologist’s diagnostic armamentarium. Step Two: Examining the Individual’s • Sound localization and lateralization: The Functional Difficulties and Sequelae ability to localize a sound source and similar skills also are complex behavioral processes The second step in customizing APD inter- that underlie many of the previously men- vention is to determine how the underlying tioned auditory abilities. One measure that auditory deficit relates to (or co-exists with) DEFICIT-SPECIFIC INTERVENTION/BELLIS 291 functional learning, language, and communica- BS/BI dysfunction, typically hearing in noise tion sequelae in the individual. To this end, and other binaural abilities are good because Bellis and Ferre10–12,14 developed a model of of preserved auditory closure, discrimination, APD in which information from central audi- performance with degraded acoustic signals, tory and multidisciplinary evaluations is used and related abilities. Secondary sequelae to create functional deficit profiles for both di- often include difficulties in perceiving stress, agnostic and intervention purposes. Each of rhythm, and intonational patterns of speech these profiles yields specific, neurophysiologi- leading to poor comprehension of commu- cally tenable patterns of findings on diagnostic nicative intent and frequent misunderstand- tests of central auditory function as well as on ings or miscommunications; poor pragmat- measures of cognition, communication, and ics, or social communication skills; and poor learning. Briefly, the three primary profiles of music or singing skills. Associated sequelae the Bellis/Ferre model are: can include reading and spelling difficulties confined to right-hemisphere-based, Gestalt • Auditory Decoding Deficit: Characterized patterning, sight-word abilities; difficulties primarily by a deficit in MSC, Auditory De- with sequencing information; and deficits in coding Deficit represents dysfunction in the other abilities attributed to the right hemi- primary (usually left) cerebral hemisphere. sphere, including mathematics calculation and Additional auditory deficits often are seen in visual-spatial tasks. auditory discrimination of minimally contrast- • Integration Deficit: The result of inefficient ing speech sounds and fundamental temporal communication between the two cerebral processes, including gap detection. Diagnos- hemispheres, Integration Deficit is primarily tically, Auditory Decoding Deficit results in characterized by deficits in BI and BS. Cen- poor performance on monaural tests of de- tral auditory testing yields a pattern of left- graded speech and binaural or right-ear defi- ear deficit on dichotic speech tasks, combined cits on dichotic speech tests. Secondary deficits with poor performance on tests of temporal may be seen in the areas of BI and/or BS, as patterning in the verbal report condition only. dichotic tests inherently reduce the extrinsic Sound localization abilities also may be poor. redundancy of the speech signal through Associated sequelae may include difficulty competition. Secondary sequelae associated across modalities with any task requiring with Auditory Decoding Deficit include sig- interhemispheric integration. Separating a nificant difficulty hearing in noise, reading sound source from a competing background and spelling difficulties usually confined to of noise may be problematic, as may associat- phonological decoding (or word attack) skills, ing a speech sound with the orthographic poor vocabulary and other language-based symbol on the page during reading or spell- concerns, auditory fatigue, and better perfor- ing, linking the prosodic and linguistic ele- mance with visual or multimodality augmen- ments of speech to arrive at an understand- tation. ing of the entire message (especially when • Prosodic Deficit: Also referred to as right- forms such as sarcasm are employed), and ac- hemisphere APD, Prosodic Deficit is char- tivities requiring bimanual or bipedal coordi- acterized by a deficit in APTO, particularly nation. The addition of visual or multimodal- as related to perception and recognition of ity cues often confuses, rather than clarifies, tonal patterns. Frequency, duration, and in- the message for individuals with Integration tensity difference limens also may be ele- Deficit. vated. Central auditory diagnostic findings include poor performance on duration and/or Readers are cautioned that these three pri- frequency pattern testing in both humming mary profiles are not the only manner in which and labeling report conditions combined APD can manifest itself. Secondary profiles with left-ear deficit on dichotic speech tests. that affect language, executive function, and Although this latter finding may suggest that planning more overtly also are possible.10–12,14 individuals with Prosodic Deficit also exhibit Isolated deficits that impact performance on 292 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

just one diagnostic test or in just one auditory Putter-Katz et al, and by Jirsa (this issue, pages area also can exist. These profiles can occur 357–364 and pages 349–356, respectively). singularly or in combination; however, one profile is typically primary and the combinations usually arise from anatomically adjacent SUMMARY AND DIRECTIONS FOR brain areas. If a child or adult exhibits deficits FURTHER RESEARCH in all auditory processes assessed, or a combination of all three profiles, one should look to This article has described the rationale under- more global, higher-order cognitive, memory, lying deficit-specific intervention for APD and or related dysfunction rather than APD as a methods of developing individualized manage- primary condition affecting listening and re- ment and intervention plans. The approach lated abilities. suggested here is largely theoretical in nature, with intervention recommendations arising logically from the specific auditory deficit(s) and Step Three: Selecting the Appropriate functional behavioral sequelae present in a given Management Strategies and individual. However, readers should be aware Remediation Techniques that a great deal of further research is needed to support empirically the approach and activi- Once the underlying auditory deficit(s) and ties described in this article. the secondary or associated functional difficul- Although it generally is accepted that to ties are determined, appropriate environmental maximize neuroplasticity, direct remediation modifications, compensatory strategies, and activities for APD should be frequent, intense, direct treatment options can be selected that and challenging, the minimum amount of time will address the individual’s APD in a deficit- and effort needed to effect a maximum change specific manner. Intervention for APD should in central auditory function has yet to be iden- arise logically from the nature of the auditory tified. Some therapy programs recommend sev- deficit(s) and the behavioral sequelae the indi- eral weeks of intense, daily activity. However, vidual is experiencing. Table 1 outlines some Tremblay and colleagues23 have shown that appropriate management and intervention tech- significant changes in behavioral perceptual niques for each of the above-mentioned per- abilities and neural representation of speech formance deficit profiles. It should be empha- can occur after just five days of directed train- sized that the information contained in this ing, and can generalize to other, untrained stim- table is not intended to provide a cookbook ap- uli. Because therapy is costly in terms of both proach to APD intervention, but rather to money and time, research is needed to deter- serve as a general guide to the types of activi- mine the frequency and intensity of therapy ties and modifications that may be indicated that is necessary but sufficient to achieve de- for these specific profiles. sired results. Moreover, we may find that deficit-specific training is not as crucial to, nor as predictable Step Four: Monitoring of, functional outcomes as might be anticipated. Intervention Efficacy Gillam and colleagues24–25 assessed language changes in children with language impairment Although a discussion of documentation of using two completely different, computer- treatment outcomes is not within the scope of assisted language intervention programs that this paper, it is critical that the efficacy of all used different types of auditory stimuli, em- intervention techniques be monitored on an ployed different language units, targeted differ- ongoing basis and alterations to the individual- ent levels of language, and were designed to im- ized program made as needed. For additional prove different aspects of language. Despite information regarding monitoring treatment these differences, they found astonishingly sim- efficacy, readers are referred to the articles by ilar improvements following treatment. Because DEFICIT-SPECIFIC INTERVENTION/BELLIS 293 (speech-to-print) skills (speech-to-print) stimuli, sound localization visual augmentation attack word awareness, new information, repetition, information, new induction listening, schema active critical integration, phonological of multi-modality cues strategies as needed social judgment binaural skills using dichotic pragmatics † † † † † discrimination discrimination Nonspeech-sound acoustic clarity less teacher, induction, use of prosody and temporal patterning, Temporal processes Temporal BS/BI Localization secondary or possible deficit area. † deficit Speech-sound preteach listening device, building, problem-solving, temporal resolution and/or Prosodic deficitProsodic APTO*“animated” Placement with Memory enhancement, schema of prosody, Perception Integration deficit BS/BI* use enhancements, avoid Acoustic Metalinguistic and metacognitive Interhemispheric transfer, DeficitProfileAuditory decoding MSC* Process(es) Affected Environmental seating, assistive Preferential Modifications Auditory closure, vocabulary Compensatory Phoneme discrimination, Strategies Remediation Direct Activities Table 1Table and Dysfunctional Processes Deficit Profiles Auditory Specific for Techniques and Intervention Management Selected *Primary deficit area; MSC, monaural separation/closure; BS, binaural separation; BI, binaural integration; APTO, auditory pattern/temporal ordering. auditory pattern/temporal APTO, binaural separation; BI, integration; MSC, monaural separation/closure; BS, 294 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

the efficacy of intervention for APD should be factor analysis and comparisons with SCAN. Am J assessed on the basis of functional abilities rather Audiol 2000;9:101–111 than improved auditory skills or processes, it is 4. Schow RL, Seikel JA, Chermak GD, Berent M. Central auditory processes and test measures: possible that intensity of treatment, repetitive ASHA 1996 revisited. Am J Audiol 2000;9:1–6 auditory stimulation, and engagement and mo- 5. Rees N. Auditory processing factors in language tivation of the subject are more essential to effi- disorders: the view from Procrustes’ bed. J Speech cacy and outcome than is the specific auditory Hear Disord 1973;38:304–315 skill trained.8,24–25 Only further investigation 6. McFarland DJ, Cacace AT. Modality specificity as will help to elucidate this issue. See also the ar- a criterion for diagnosing central auditory process- ticles by Phillips, and Chermak and Musiek ing disorder. Am J Audiol 1995;4:36–48 (this issue, pages 251–262 and pages 297–308, 7. Cacace AT, McFarland DJ. Central auditory processing disorder in school-aged children: a critical respectively). review. J Speech Lang Hear Res 1998;41:355–373 Finally, as discussed earlier, more data are 8. Chermak GD, Musiek FE. Central Auditory Pro- needed to fully support the basic assumptions cessing Disorders: New Perspectives. San Diego, upon which the rationale for deficit-specific CA: Singular; 1997 APD intervention is based. Data remain scarce 9. Jerger J, Musiek F. Report of the consensus confer- to validate the conceptualization of APD as an ence on the diagnosis of auditory processing disor- auditory input disorder that leads to higher- ders in school-aged children. J Am Acad Audiol order language, learning, and communication 2000;11:467–474 10. Bellis TJ. Assessment and Management of Central difficulties; that can be identified through di- Auditory Processing Disorders in the Educational agnostic central auditory tests; and that can be Setting: From Science to Practice. San Diego, CA: treated so as to foster improvements in audi- Singular; 1996 tory and related behavior. Until such time as 11. Bellis TJ, Ferre JM. Multidimensional approach to these data are obtained, the clinical utility of the differential diagnosis of central auditory pro- the APD diagnosis will remain limited and the cessing disorders in children. J Am Acad Audiol benefits of deficit-specific intervention will re- 1999;10:319–328 12. Bellis TJ. Subprofiles of central auditory processing main uncertain. disorders. Ed Audiol Rev 1999;2:9–14 13. Chermak GD. Managing central auditory processing disorders: megalinguistic and metacognitive ABBREVIATIONS approaches. Semin Hear 1998;19:379–392 14. Bellis TJ. When the Brain Can’t Hear: Unraveling the Mystery of Auditory Processing Disorder. New APD auditory processing disorder York: Pocket Books; 2002 APTO auditory pattern temporal ordering 15. Technical Committee on Architectural Acoustics. ASHA American Speech-Language-Hearing Classroom Acoustics: A Resource for Creating Association Learning Environments with Desirable Listening BI binaural integration Conditions. Melville, NY: Acoustical Society of BS binaural separation America; 2000 MSC monaural separation/closure 16. Musiek FM. Habilitation and management of auditory processing disorders: overview of selected procedures. J Am Acad Audiol 1999;10:329–342 17. Willeford JA, Burleigh JM. Sentence procedures in REFERENCES central testing. In: J. Katz, ed. Handbook of Clini- cal Audiology, 4th ed. Baltimore, MD: Williams & 1. American Speech-Language-Hearing Association. Wilkins; 1994:256–268 Central auditory processing: current status of re- 18. Musiek FE. Assessment of central auditory asym- search and implications for clinical practice. Am J metry: the dichotic digit test revisited. Ear Hearing Audiol 1996;5:41–54 1983;4:79–83 2. Schow R, Chermak GD. Implications from factor 19. Ptacek PH, Pinheiro ML. Pattern reversal in the analysis for central auditory processing disorders. perception of noise and tone patterns. J Acoust Soc Am J Audiol 1999;8:137–142 Am 1971;49:493–498 3. Domitz DM, Schow RL. A new CAPD battery— 20. Pinheiro ML, Musiek FE. Sequencing and tempo- multiple auditory processing assessment (MAPA): ral ordering in the auditory system. In: Pinheiro DEFICIT-SPECIFIC INTERVENTION/BELLIS 295

ML, Musiek FE, eds. Assessment of Central Au- novel stimuli following listening training. J Acoust ditory Dysfunction: Foundations and Clinical Soc Am 1997;102:3762–3773 Correlates. Baltimore, MD: Williams & Wilkins; 24. Gillam RB, Crofford JA, Gale MA, Hoffman LM. 1985:219–238 Language change following computer-assisted lan- 21. Keith RW. Random Gap Detection Test. St Louis, guage instruction with Fast ForWord or Laureate MO: Auditec; 2000 Learning Systems software. Am J Speech Lang 22. Phillips DP. Auditory gap detection, perceptual Pathol 2001;10:231–247 channels, and temporal resolution in speech per- 25. Gillam RB, Loeb DF, Friel-Patti S. Looking back: ception. J Am Acad Audiol 1999;10:343–354 a summary of five exploratory studies of Fast For- 23. Tremblay K, Kraus N, Carrell TD, McGee T. Cen- Word. Am J Speech Lang Pathol 2001;10:269– tral auditory system plasticity: generalization to 273

Auditory Training: Principles and Approaches for Remediating and Managing Auditory Processing Disorders

Gail D. Chermak, Ph.D.,1 and Frank E. Musiek, Ph.D.2

ABSTRACT

Recent reports suggest that auditory training (AT) can serve as a valuable intervention tool, particularly for individuals with language impairment and auditory processing disorder (APD). This article suggests a continuum of AT approaches, including those that do not require major instrumentation and can be implemented by speech-language pathologists and audiologists through their clinical practices. AT approaches are categorized as formal and informal. Formal AT is conducted by the professional in a controlled setting. Informal AT can be conducted as part of a home or school management program for APD. Formal AT employs acoustically controlled, bottom-up tasks using tones and speech elements, as well as language-based or top-down tasks. Infor- mal AT is designed to improve auditory perceptual skills through language-based, predominantly top-down tasks. Coupling formal with informal AT should maximize treatment efficacy as skills are practiced toward mastery and automatism in real world settings that establish functional significance and provide repeated opportunities for generalization of skills.

KEYWORDS: Auditory processing, auditory processing disorder, auditory training

Learning Outcomes: Upon completion of this article, the reader will be able to (1) differentiate informal from formal auditory training approaches, (2) identify at least three informal auditory training exercises and the auditory process(es) targeted, and (3) identify at least three formal auditory training exercises and the auditory process(es) targeted.

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Gail D. Chermak, Ph.D., Department of Speech and Hearing Sciences, Washington State University, Pullman, WA 99164–2420. E-mail: [email protected]. 1Department of Speech and Hearing Sciences, Washington State University, Pullman, Washington; 2Department of Communication Sciences and Otolaryngology, University of Connecticut, Storrs, Connecticut. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,297,308,ftx,en;sih00223x. 297 298 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Auditory training (AT) is designed to and exercises we suggest reflect our opinion, improve the function of the auditory system in clinical experience, and our interpretation of resolving acoustic signals. There has been re- the literature reviewed in this article. newed interest in AT recently driven by the substantial body of literature demonstrating the plasticity of the auditory system1–11 and AUDITORY PROCESSING following reports that confirm the value of AT DISORDER as an intervention tool, particularly for individuals with language impairment and auditory APD is a complex and heterogeneous group of processing disorder (APD).12–16 For an over- disorders usually associated with a range of lis- view of the neurobiology of the central audi- tening and learning deficits despite normal tory nervous system (CANS) and discussion of hearing sensitivity.18–21 Jerger and Musiek stated the role of plasticity in AT, see the articles by that APD “may be broadly defined as a deficit Phillips and Museik et al (this issue, pages in the processing of information that is specific 251–262, and pages 263–276, respectively). to the auditory modality.”21 More specifically, The purpose of this article is to describe a Chermak and Musiek described APD as “a continuum of AT approaches, including those deficit observed in one or more of the central that do not require major instrumentation, and auditory processes responsible for generating can be implemented by speech-language pathol- the auditory evoked potentials and the follow- ogists and audiologists through their clinical ing behaviors: sound localization and lateral- practices. These approaches are designed pri- ization; auditory discrimination; auditory pat- marily for children diagnosed with APD; how- tern recognition; temporal aspects of audition ever, many exercises can be adapted for use including, temporal resolution, temporal mask- with adults and for clients with other disor- ing, temporal integration, and temporal order- ders, including peripheral hearing loss (see the ing; auditory performance with competing section on Principles of Auditory Training, pre- acoustic signals; and auditory performance with sented later in this article). Given the scarcity degraded acoustic signals.”19 Given the range of published information about AT, coupled of listening and learning deficits associated with the growing body of literature suggesting with APD, AT must be seen as only one com- the potential benefit of some types of AT for ponent of a comprehensive management ap- remediation and management of APD,5,8,12,14–17 proach to improving auditory processing. The it is crucial that audiologists and speech-language reader is referred to companion articles in this pathologists undertake AT to ascertain the rela- issue, as well as the authors’ other work on this tive efficacy of the various approaches and ex- topic for a thorough discussion of the range of ercises, including those outlined in this article. intervention approaches useful in managing The approaches and tasks described in this ar- APD, including linguistic, metalinguistic and ticle follow from the authors’ theoretical frame- metacognitive strategies, acoustic signal en- work18,19 and professional consensus20 and are hancement, and environmental modifications.19 in use in the authors’ clinics. Preliminary data reported by Musiek revealed improvements in central auditory test scores, as well as improved PRINCIPLES OF AUDITORY academic and communicative performance TRAINING among 15 children between the ages of 8 and 13 years who underwent formal AT as described AT can be employed to improve auditory pro- here.14 It must be emphasized, however, that cessing abilities in a number of clinical popula- the approaches we suggest are among a num- tions presenting auditory deficits due to con- ber of possible approaches that ultimately may firmed CANS pathology (e.g., traumatic brain be deemed efficacious for the treatment of APD. injury, aphasia, progressive neurodegenerative The principles we delineate and the approaches disorders), as well as in cases of suspected CANS AUDITORY TRAINING FOR AUDITORY PROCESSING DISORDERS/CHERMAK, MUSIEK 299 pathology (e.g., learning disabilities, language deficits in the absence of auditory performance impairment, attention deficit disorders). A com- deficits for degraded signals. Tasks should be prehensive audiologic evaluation, supplemented presented systematically and graduated in diffi- as needed with language and psychoeducational culty to be challenging and hence motivating, evaluations, as well as feedback from parents but not overwhelming. We find that targeting and teachers, must be conducted prior to im- accuracy between 30 to 70% allows for suffi- plementing any AT program. These measures cient practice and challenge while maintaining should be re-assessed periodically to ascertain the client’s motivation and on-task persistence. progress, redirect therapy if necessary, and ter- Nonetheless, the clinician should determine the minate therapy if the client has attained the criterion appropriate for each client. Detection maximum benefit that can be expected. Gener- and discrimination tasks should precede more ally, younger subjects can be expected to bene- demanding psychoacoustic tasks requiring iden- fit from AT to a greater degree due to neural tification, recognition, and production. We rec- plasticity.22 Children whose auditory deficit is ommend that clients attain a minimum of 70% associated with a neuromaturational lag can be accuracy before proceeding to the more de- expected to benefit from intense AT as stimu- manding tasks. To the extent possible, AT lation extends plasticity and the purported sen- should be conducted in an intensive manner, sitive periods for learning, thereby maximizing scheduling multiple sessions, perhaps 5 to 7 ses- the potential for successful rehabilitative ef- sions weekly.14 Generally, exercises should be forts.3,23,24 Similarly, individuals with auditory presented at the client’s comfortable listening deficits secondary to brain damage can profit level, although slightly louder presentations may from AT that stimulates and challenges dam- produce more clear speech and ease the listening aged neural networks and induces neural reor- task.25 ganization.24 In either case, the degree of neu- The ultimate goal of AT, and therefore the ronal change and maturation is dependent on true measure of the efficacy of an AT program, the quality and consistency of stimulation. is measured in functional abilities (i.e., improved Auditory maturation must be considered listening comprehension, spoken language pro- in designing auditory tasks and establishing cessing, and educational achievement).26,27 Data criterion performance. Some of the AT tasks confirming treatment efficacy are derived from reviewed in this article are appropriate for multiple measures that are sufficiently broad to preschool-aged children (e.g., auditory dis- document the client’s progress in deploying the crimination, auditory directives, and reading newly acquired or enhanced processing strate- aloud); other AT tasks demand greater cogni- gies and skills in a variety of contexts.19 Repeat tive sophistication and would be more appro- administration of auditory processing tests (e.g., priately used with older children and adults dichotic digits, pitch patterns, gap detection) are (e.g., intensity and frequency training). less useful in establishing treatment efficacy and A variety of stimuli and tasks should be may instead reveal a learning effect.28 Measures used to train auditory processes. If the client of speech recognition in competition and recog- presents an auditory deficit restricted to a spe- nition of time-compressed speech, for example, cific auditory region or auditory process, a more provide more functional indices of the status of narrowly designed AT program might be ap- binaural and temporal auditory processes than propriate. For example, subjects with both tem- do dichotic digits and pitch pattern tests, re- poral processing deficits and auditory perfor- spectively. Performance scales and inventories mance decrements for degraded acoustic signals also may serve as useful outcome measures.29–31 might benefit from exercises requiring recogni- Musiek’s report of improved communication tion of time-compressed speech. In contrast, function and academic performance in 9- to 11- gap detection might be a more appropriate ex- year-old children following AT, as outlined in ercise to specifically train temporal processing this article, illustrates the types of measures for subjects presenting temporal processing needed to confirm efficacy of AT.14 300 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

AUDITORY TRAINING APPROACHES ogist or educational audiologist, families, and teachers who employ informal AT approaches The authors categorize AT approaches as for- in the home or classroom setting. mal and informal. Formal AT is conducted by A variety of habilitation techniques can be the professional in a controlled setting (i.e., a employed to improve auditory processes, as illus- clinic or laboratory). Informal AT can be con- trated in Table 1. Clinical decisions to target one ducted as part of a home or school manage- or more auditory processes are based on the re- ment program for APD. Coupling formal with sults of specific auditory tests and procedures, as informal AT should maximize treatment effi- well as reports of functional, real-world deficits. cacy as skills are practiced toward mastery and (The reader should note that interhemispheric automatism in real world settings that establish transfer, while not a specific auditory perceptual functional significance and provide repeated skill, is included in Table 1 because it underlies opportunities for generalization of skills. binaural processing required for auditory separation and auditory integration.) Some AT tasks target more than one audi- Formal Auditory Training Tasks tory process. For example, intensity training may benefit localization and lateralization, au- Formal AT employs rigorous, acoustically con- ditory vigilance, and auditory discrimination.32 trolled training paradigms using bottom-up (i.e., Similarly, training dichotic listening may analytic) tasks with nonverbal signals (e.g., improve binaural separation and binaural inte- tones) and simple speech elements (e.g., dis- gration. Perhaps most important, formal AT criminating paired consonant-vowel [CV] syl- should benefit spoken language processing by lables) to target specific auditory processes. improving the auditory processes essential func- Formal AT to improve temporal processing tion in resolving auditory signals. For example, might target gap detection and ordering of two improved temporal processing should strengthen or three rapidly presented acoustic elements, resolution of prosodic detail underlying mean- varying the interstimulus interval and/or stim- ingful distinctions between heteronyms, as well ulus duration to alter task difficulty. Formal as distinctions of temporal cueing (e.g., “They AT may involve language-based or top-down saw the car go on the ferry” vs. “They saw the tasks (e.g., resolving semantic distinctions sig- cargo on the ferry.”). Targeting recognition of naled by temporal cues; using a phonemic expanded or compressed words or speech seg- analysis task to exercise auditory discrimination; ments should improve auditory closure. resolving prosodic distinctions to challenge Examples of commercially available for- temporal resolution). mal AT programs include Fast ForWord (avail- Formal AT programs have many advan- able from Scientific Learning Corp., Berkley, tages, including the ability to specify and pre- CA) and Earobics™ (available from Cognitive cisely alter acoustic stimuli. The acoustic com- Concepts, Inc., Evanston, IL). Both programs position of the stimuli, as well as their rate of involve computer-mediated presentations of presentation, can be controlled using computers acoustically modified stimuli.The Earobics pro- and other instrumentation. Presentation of con- gram, as well as Away We Go (also available trolled stimuli through adaptive computer pro- from Scientific Learning Corporation), can be grams engages the listener and ensures the task employed on the home computer (in support of is maintained at the appropriate difficulty level. informal AT), as well as in the professional clin- In addition, computer software can simplify the ical setting. See the articles by Musiek et al, and monitoring of performance. Generalization of by Phillips (this issue, pages 263–276, and pages auditory perceptual skills from clinic or labora- 251–262, respectively), for a discussion of soft- tory to real-world settings (e.g., school, work- ware for AT. While these commercially available place, playground) may not occur readily; how- tools for formal AT require instrumentation, ever, unless formal AT is extended through other formal AT activities can be administered collaboration with the speech-language pathol- in a clinical setting with minimal if any instru- AUDITORY TRAINING FOR AUDITORY PROCESSING DISORDERS/CHERMAK, MUSIEK 301 left-sided motor response to verbal command motor response to verbal left-sided increments/transitions; discriminate duration tones or CVs; for increments/gaps/differences phonemic synthesis phonemic analysis, identify word boundaries via temporal cueing; reading identify word auditorypoetry; directives follow listen to intensity imbalanced stereo music; auditory vigilance recognition in competition; listening; speech dichotic listen to intensity imbalanced stereo music; auditory vigilance position while drawing; hand; describe picture held in left duration; distorted speech recognitionduration; distorted speech compressed speech)(e.g., filtered speech; increments; discriminate frequency discriminate intensity syllables, tones, or words; compressed speech)fusion or gap detection in sentence context and acoustically degraded words differentiation; tasks; prosody training; heteronym speech recognition in competitionspeech recognition in competition; listening; speech dichotic (binaural interaction) ProcessAuditory discrimination and frequency, intensity, limens for Difference Assessment Test/Procedure comparisons of phonemes, Auditory vigilance; Paired (Re)Habilitation Table 1 Selected Formal and Informal Auditory Training Techniques Targeting Specific Auditory Processes Auditory Specific Targeting 1Techniques Table Training Auditory and Informal Formal Selected Auditory closure analysis/synthesisTemporal perception; click element ordering; pattern Two recognition (e.g. filtered speech; speech Distorted detection; duration discrimination; sequencing Gap words vocabulary building; recognize Miller-Gildea Binaural separation recognition; diotic speech dichotic Directed listening; temporally altered Intensity altered dichotic Binaural integration/summation lateralizationLocalization, recognition speech dichotic Nondirected Interhemispheric transfer localization/lateralization rhyme; Dichotic listening; temporally altered Intensity altered dichotic perception Pattern target detection in sound-field with changing Signal identification through tactile cues of objects Verbal 302 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

mentation required. Auditory vigilance training the modulation rates are the same or different can be accomplished by presenting various stim- and, if different, to identify which of the two uli (live voice or recorded), varying the time tones is modulated at a faster rate. between presentations. Similarly, temporal or- Another frequency training task involves dering can be targeted by asking clients to de- ascending and descending frequency sweeps of termine the order in which tones or syllables are varying glide rates. The sweep range is usually presented. The tasks outlined here are typically less than 10% of the frequency of the base tone. presented in the sound field at a most comfort- The client’s task is to determine whether a able listening level. change has occurred and if so in which direction (i.e., low to high or high to low frequency).

Intensity Training Temporal Training Intensity training may be indicated on the basis of reduced difference limens for intensity. Temporal training tasks are indicated by poor Intensity discrimination training requires the performance on the Pitch Pattern Test and client to discern an intensity increment that Duration Pattern Test.34 Cognate pairs (e.g., is superimposed on a continuous tone of the /pa/ vs. /ba/) that are distinguished by their same frequency. We have found that an inten- voice-onset times (VOT) provide stimulus ma- sity increment varied from 1 to 5 dB, approxi- terial for temporal training. Clients can be mately 300 msec in duration, and with a 50 trained to discriminate and identify CV pairs msec rise/fall time provides a success-to-failure as different (/ba/, /da/) or the same (/ba/, /ba/), ratio needed to maintain challenge as well as varying the interstimulus interval to adjust dif- motivation. ficulty level.16 Gap detection offers another approach to temporal training. Stimuli consist of 10 sec periods of broadband noise with two or Frequency Training three interruptions (gaps). The gaps or silent intervals are systematically varied to permit the appropriate range of performance. Ordering of Training on frequency discrimination and tran- two or three rapidly presented acoustic elements sitions may be indicated by poor performance also targets temporal processing. The clinician on the Pitch Pattern Test.33 A frequency detec- may alter the interstimulus interval and/or du- tion task requires the client to detect frequency ration of the stimuli to adjust task difficulty. modulations (i.e., pitch variations) of continuous tones (approximately 5 sec in duration). The degree and rate of frequency modulation are adjusted to attain the desired success-to- Speech Recognition Training failure ratio. The frequency of the modulation tone can be varied from session to session to Speech recognition training in various compet- span across low, mid, and high frequencies. ing conditions builds on a number of auditory Discriminating and identifying differences processes, including auditory discrimination in modulation rates offers a more challenging and temporal processing. Poor performance on task involving both frequency and temporal dichotic listening or compressed/reverberant processing abilities. The client is asked to com- speech recognition tests suggests a need for pare the modulation rates of two successive speech recognition training. tones, each approximately 1 sec in duration with The speech recognition task can be con- a 1 sec interstimulus interval. The degree of ducted to train binaural separation and binau- frequency modulation is held constant at a fre- ral integration. In the first variation, the client quency difference easily recognized by the client. is required to direct attention to the loudspeaker The client’s task is to first determine whether delivering the less intense stimuli, while ignor- AUDITORY TRAINING FOR AUDITORY PROCESSING DISORDERS/CHERMAK, MUSIEK 303 ing the stimuli presented through the second training integrative functions. Moreover, infor- loudspeaker (i.e., binaural separation). In the mal AT offers potential for broader impact, as second variation, the client is asked to attend a number of informal techniques improve lan- to both loudspeakers (i.e., binaural integra- guage skills as well as auditory skills. For exam- tion). The intensity of the stimuli in both con- ple, discrimination and recognition of degraded ditions varies in 10-dB steps, with 5 to 10 trials speech stimuli (e.g., time compressed or filtered at each intensity. Words, sentences and conso- speech) can be used to improve auditory clo- nant-vowel-consonant syllables (CVC) may be sure. These same speech stimuli presented in used as stimuli. Stimulus intensity should be sentences can be used to build vocabulary (i.e., varied to achieve the desired success-failure context-derived vocabulary building).19 Simi- rate. Competing speech may be added to the larly, prosody training with heteronyms target binaural speech recognition task to increase temporal processing while also aiding vocabu- difficulty. Stimuli should be presented at 50 dB lary development.19 HL, or comfortable listening level, and speech- Informal AT offers substantial opportunity to-competition ratios should be adjusted to en- for generalization of newly learned skills and sure challenge and maintain motivation. strategies. Informal AT provides a wide variety of AT stimuli, contexts, and tasks, all of which foster generalization of skills. Because these programs Informal Auditory Training can be undertaken at home and in school, informal AT allows for additional practice that pro- Employing verbal stimuli and emphasizing the motes mastery and generalization of skills and use of linguistic context to benefit auditory func- maximizes the efficacy of the treatment program. tion, informal AT offers a complementary and In addition to the specific methods below, more synthetic approach to AT. Informal AT is the professional may adapt many tests of cen- designed to improve auditory perceptual skills tral auditory processing for use as therapy ma- through language-based, predominantly top- terials. For example, temporal gap detection down tasks. Because required instrumentation may be trained using the Auditory Fusion is minimal, AT can be conducted in the home Test-R.35 (or the revised form, the Random or school, as well as by the speech-language Gap Detection Test). Temporal sequencing may pathologist or the educational audiologist in the be trained using the Duration Patterns Test.34 clinic. The speech-language pathologist can use Auditory directives may be trained using the informal AT to train the same auditory pro- Token Test for Children.36 Auditory vigilance cesses targeted by the audiologist, who, because may be targeted using the Auditory Continu- of access to particular instrumentation, would ous Performance Test.37 The speech-language more likely administer formal AT techniques. pathologist should make the decision to use test For example, binaural separation (i.e., selective materials for therapy in collaboration with the listening) and binaural integration (i.e., divided audiologist who may plan to re-administer these attention) can be trained through formal AT tests as one measure of progress in therapy. using intensity altered and temporally altered Using the same test for assessment and therapy dichotic tasks. These same skills can be trained could lead to a situation where the subject’s informally with a two-channel stereo system, performance on repeat testing reflects familiar- using the balance control to adjust the inten- ity with the test (i.e., learning effect) rather than sity of the two channels. Similarly, informal a true measure of auditory function. tasks requiring the following of sequenced, au- The following informal AT methods rely ditory directives can be paired with formal tasks on equipment readily available to most speech- requiring ordering of rapidly presented acous- language pathologists and educational audiol- tic elements of varying interstimulus interval ogists. Preliminary data support the potential and/or duration to target temporal processing. of these methods to improve the communica- Informal AT programs tap multiple pro- tion and academic performance of children cesses concurrently, which can be helpful in with APD.14 304 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Auditory Discrimination Training blends. Consonant pairs sharing few acoustic features will be easiest to discriminate. Training Auditory discrimination is perhaps the most can be extended to sentence contexts, providing fundamental auditory processing skill underly- a transition to therapy directed to auditory clo- ing spoken language comprehension.19 The sure and vocabulary building.19 Construction of ability to perceive acoustic similarities and dif- a confusion matrix of vowel, consonant, and word ferences between sounds is essential (but not discrimination errors can help direct training sufficient) for segmentation skills and phone- toward more frequently occurring errors. As mic analysis and synthesis. the child masters these errors, these sounds are Children with APD often experience diffi- removed from the high-error pool and atten- culty discriminating and identifying vowels, per- tion is directed to discriminating items that re- haps reflecting an interaction between classroom main challenging to the child. acoustics and auditory perception.14 Because the As noted previously, auditory discrimi- background or ambient classroom noise has a nation exercises also tax and therefore train au- spectrum that is often similar to many of the low ditory attention. Similarly, auditory discrimi- frequency vowels,38,39 many distinctive acoustic nation tasks can be used to train temporal elements that are key to distinguishing and iden- processing by requiring the child to distinguish tifying vowels are masked. Auditory discrimina- heteronyms and identify vowels in proper se- tion training for vowels should be conducted in a quence. Sloan’s four-part AT program devel- quiet environment, without visual cues, although ops auditory discrimination, sound analysis, it may be necessary to initially provide visual in- and phoneme-grapheme association skills and formation that is then removed as the client applies these skills to reading and spelling of achieves some success. words.40 The clinician must ascertain that the child understands metalinguistic concepts (e.g., the meaning of long versus short vowels, sound Auditory Discrimination Training position in words, phoneme-grapheme corre- for Young Children. spondence rules, etc.) before proceeding. In- formal vowel training progresses through a For most preschool children, discriminating hierarchy of steps. First the child is asked to differences among sounds is a challenging, yet identify the sound corresponding to each of engaging, task. Environmental sounds differ- the vowel graphemes, as these graphemes are ing in intensity, frequency, duration, and qual- written for the child. Next, the clinician pre- ity can be used to develop auditory discrimina- sents the vowel sounds auditorily, asking the tion. The child might be asked to state which child to point to or state the corresponding of three bells of different pitch has the highest, grapheme, denoting long or short. Vowels may middle, and lowest pitch or to identify differ- then be presented for identification in context ent, familiar voices. To increase task difficulty, using CV and CVC stimuli and words. speakers can alter their voices, speak quickly, Once the child’s understanding of pho- say short words or CV combinations, or use a neme-grapheme correspondence has been es- combination of these modifications.41 Playing tablished, auditory discrimination training com- games with toy animals (“The cow says moo, mences with paired (same-different judgments) the sheep says baaa.”) and picture or sticker comparisons of vowels. The task can be gradu- pointing games (“Show me the cat.”) also train ated in difficulty by presenting vowels with in- auditory discrimination and identification.42 creasingly more similar acoustic structure (i.e., those closer together in the vowel quadralat- eral). The child should be directed to listen for Prosody Training the subtle acoustic changes that mark vowels coarticulated in syllabic and word (rhyming) con- Prosody guides attention to the most informa- texts. Auditory discrimination training can be tive parts of the message, provides information focused on single consonant and consonant about lexical, semantic, and syntactic aspects of AUDITORY TRAINING FOR AUDITORY PROCESSING DISORDERS/CHERMAK, MUSIEK 305 the spoken message, and also helps establish Reading poetry is another useful activity auditory memory patterns important to lan- to improve temporal processing of speech guage.43–47 Also known as acoustic contour rhythms.14 Having the child mimic a cadence recognition, discrimination and identification of simple finger tapping or sequence of notes of prosodic features (e.g., intonation, rhythm, on a piano also can be used as a form of tempo- and acoustic stress) require the perception of ral training. rather subtle and rapid temporal, frequency, and intensity changes.47 Because individuals with APD often do not have good frequency, Auditory Directives temporal or intensity discrimination,48,49 prosody and intonation cannot be appreciated fully. The ability to follow auditory directions is an Informal auditory training for recognition essential life skill and is key to academic success. of rhythm, prosody, and intonation can be ac- Following auditory directives can be trained complished in a variety of ways. One approach within naturally occurring (i.e., authentic) con- similar to the temporal tasks employed by Tal- texts in which the individual must follow se- lal and colleagues16 is to require clients to audi- quenced directives to successfully complete a torily define word boundaries and intervals be- task, as well as through the use of games that tween words. The client is given words with require the child to follow directions presented one segment stressed and asked to identify the auditorily.41 stressed segment and repeat the word with The child should be asked to repeat the di- stress on the appropriate syllable. For example, rective before executing the motor task to en- a city in Ohio can be said in three different hance reauditorization and auditory memory. ways with stress on three different syllables, as Requesting motor activity rather than simply follows: Ashtabula, Ashtabula, Ashtabula. requiring repetition of the directive ensures that Sentences with varying prosodic cues can the client integrated the auditory input with rel- be used as therapy material to demonstrate how evant knowledge and motor commands in com- prosodic changes alter meaning. For example, pleting the required task. Moreover, the motor the meaning of the following phrase changes task will channel excessive motor activity pre- as emphasis is placed on different words: Look! sented by children whose APD co-exists with out the window; Look out! the window; Look attention deficit hyperactivity disorder (ADHD). out the window. The pitch, intensity, and dura- The impulsivity of children with ADHD should tion variations that signal proper segmentation be counteracted by instructing them not to and change meaning should be discussed. perform the motor task until the directive(s) Sentences in which temporal cues signal has been completed. word boundaries and change meaning also pro- Auditory commands should progress in vide opportunity to train auditory closure and difficulty level from simple to complex, involv- build vocabulary. Subtle timing cues mark dis- ing one or multiple sequenced actions.14,41 tinctive differences in meaning as illustrated in Group actions requiring cooperation among the following sentences, taken from Cole and children may be used, and children can be given Jakimik.50 Resolution of prosodic detail is neces- the chance to act as clinicians (i.e., reciprocal sary to properly segment and derive the correct teaching) by generating directives for others to meaning of ambiguous words in these sentences. follow. Reciprocal teaching expands practice opportunities while building confidence and “The doctor said that nose drops will help self-esteem.19 the cold.” Directives can be presented in the context “The doctor said that he knows drops will of a game format. The Token Test for Children help the cold.” can be used as material for auditory directives.36 Incorporating this type of therapy outside the “He just hated forgetting the right number.” clinical setting (e.g., in the classroom, at home in “He was noted for getting the right the context of chores, or in recreational settings) number.” should maximize generalization. An example of 306 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

the latter would be in teaching a child how to ered optimal for remediating APD, it is now swing a tennis racket or a golf club while also recognized that regular and consistent practice, teaching the game of tennis or golf, respectively. perhaps even for 10 to 15 minutes daily for a number of weeks, provides the intensity of focus and training needed to maximize success.16 Al- Auditory Vigilance Training though economic, time, and motivational factors certainly influence the length of time ther- Auditory vigilance involves sustaining a high apy can be provided, optimally, progress toward level of auditory attention for necessary peri- meeting therapy objectives should be the pri- ods of time in anticipation of a target stimulus. mary guide to decisions regarding scheduling Auditory vigilance is usually trained by asking and terminating therapy. a client to listen for a target stimulus presented at random or at pseudo-random intervals within a series of other auditory events. One might, ABBREVIATIONS for example, read a story to a child (or group of children), designating a target item (e.g., all words that end in the “d’ sound or any word ADHD attention deficit hyperactivity disorder that has to do with food). The more random APD auditory processing disorder the target presentation and the greater the in- AT auditory training terval between targets, the more challenging CANS central auditory nervous system the task. This type of activity is appropriate CV consonant-vowel syllables for children in preschool or early elementary CVC consonant-vowel-consonant syllables grades and can be adapted for use with older clients as well. For example, the target might be subtle prosodic elements, thereby training REFERENCES prosody in the context of an auditory vigilance exercise. The option to use a wide variety of 1. Edeline JM, Weinberger NM.Thalamic short-term target stimuli gives the auditory vigilance para- plasticity in the auditory system: associative retun- digm flexibility to train other auditory pro- ing of receptive fields in the ventral medial genicu- cesses while accommodating clients of varying late body. Behav Neurosci 1991;105:618–639 age and ability. 2. Elbert T, Pantev C, Wienbruch C, Rockstroh B, Taub E. Increased cortical representation of the fingers of the left hand in string players. Science 1995;270:305–306 CONCLUSIONS 3. Hassamannova J, Myslivecek J, Novakova V. Ef- fects of early auditory stimulation on cortical areas. Given the range of listening and learning deficits In: Syka J, Aitkin L, eds. Neuronal Mechanisms of associated with APD, AT must be seen as only Hearing. New York: Plenum Press; 1981:355–359 one component of a comprehensive manage- 4. Irvine DRF, Rajan R, McDermott HJ. Injury- induced reorganization in adult auditory cortx and ment approach to improving auditory process- its perceptual consequences. Hearing Res 2000; ing. Coupling formal with informal AT should 147:188–199 maximize treatment efficacy. Collaboration 5. Knudsen EI. Experience shapes sound localization among professionals administering these ther- and auditory unit properties during development apies is crucial to the success of AT. The in- in the barn owl. In: Edlman G, Gall W, Kowan W, volvement of families in home practice is cru- eds. Auditory Function: Neurobiological Basis of cial because many children with APD do not Hearing. New York: John Wiley; 1988:137–152 qualify for special services in many school dis- 6. Merzenich M, Jenkins W. Cortical plasticity, learning and learning dysfunction. In: Julesz B, tricts. Those who do qualify may not receive Kovacs I, eds. Maturational Windows and Adult sufficient school-based therapy to achieve their Cortical Plasticity: SFI Studies in the Sciences of potential. Although there is little empirical Complexity, vol. XXIII. Reading, PA: Addison- data relating to the amount of practice consid- Wesley; 1995: 247–272 AUDITORY TRAINING FOR AUDITORY PROCESSING DISORDERS/CHERMAK, MUSIEK 307

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Olswang LB, Bain B. Data collection: monitoring adult owl monkeys. J Neurosci 1993;13:87–103 children’s treatment progress. Am J Speech Lang 10. Weinberger NM, Diamond DM. Physiological Pathol 1994;3(3):55–66 plasticity in auditory cortex: rapid induction by 28. Yencer KA. The effects of auditory integration learning. Prog Neurobiol 1987;29:1–55 training for children with central auditory process- 11. Willott JF, Aitken LM, McFadden SL. Plasticity ing disorders. Am J Audiol 1998;7:32–44 of auditory cortex associated with sensorineural 29. Anderson KL. S.I.F.T.E.R.: Screening Instrument hearing loss in adult mice. J Comp Neurol 1993; for Targeting Educational Risk. Austin, TX: Pro 329:402–411 Ed, 1989 12. Jirsa RE.The clinical utility of the P3 AERP in chil- 30. Anderson KL, Smaldino J. Listening Inventories dren with auditory processing disorders in school- for Education (L.I.F.E.). Tampa, Fl: Educational aged children. J Speech Hear Res 1992;35:903–912 Audiology Assoc; 1998 13. 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43. Goldinger SD, Pisoni DB, Luce PA. Speech per- 48. Bornstein SP, Musiek FE. Implication of temporal ception and spoken word recognition: research and processing for children with learning and language theory. In: Lass NJ, ed. Principles of Experimental problems. In: Beasley D, ed. Contemporary Issues Phonetics. St. Louis, MO: Mosby; 1996:277–327 in Audition. San Diego, CA: College-Hill Press; 44. Cutler A, Foss DJ. On the role of sentence stress in 1984:25–65 sentence processing. Lang Speech 1977;20:1–10 49. Thompson M, Abel S. Indices of hearing in pa- 45. Studdert-Kennedy M. Speech perception. Lang tients with central auditory pathology. II: Choice Speech 1980;23:46–66 response time. Scand Audiol 1996;21:17–22 46. Valett RE. Developing linguistic auditory memory 50. Cole R, Jakimik J. A model of speech perception. patterns. J Lear Disabil 1983;16:462–466 In: Cole R, ed. Perception and Prediction of Fluent 47. Handel S. Listening: An Introduction to the Per- Speech. Mahwah, NJ: Lawrence Erlbaum; 1980: ception of Auditory Events. Cambridge, MA: 133–160 MIT Press; 1989 Classroom Acoustics and Personal FM Technology in Management of Auditory Processing Disorder

Gail Gegg Rosenberg, M.S.1

ABSTRACT

Acoustical conditions in the classroom, home, and social environments are often barriers to listening and learning for students with auditory processing disorder (APD). The effective management of APD requires careful attention to classroom acoustics and the use of personal frequency modulated (FM) systems as strategies to improve the quality of the listening environment and the student’s access to acoustic information. As members of the multidisciplinary team responsible for both auditory assessment and management, audiologists have the responsibility to guide the evaluation of the listening environment and make recommendations for modifications, as well as the selection, fitting, and monitoring of personal FM technologies. Demonstrating efficacy is an essential part of the management process. Audiologists are challenged to contribute to the research base by collecting data to support the use of personal FM systems as an efficacious management strategy.

KEYWORDS: Auditory processing disorder, profiles, personal FM, classroom management

Learning Outcomes: After reading this article, the reader will be able to (1) discuss the quantitative and qualitative indicators identified through the assessment process that support the use of a personal FM system as an APD management tool, (2) identify the APD profile characteristics that support the use of FM technology as an APD management tool, and (3) organize and implement training and efficacy measures related to the use of FM technology as an APD management tool.

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Gail Gegg Rosenberg, M.S., Director, Special Needs Education, Interactive Solutions, Inc., 6448 Parkland Drive, Sarasota, FL 34243. E-mail: [email protected]. 1Vice President, Interactive Solutions Incorporated, Sarasota, Florida. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,309,318,ftx,en;sih00224x. 309 310 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Acoustical conditions in the classroom, needs; and (4) ensuring that the student and home, and social environments can present se- teacher receive inservice training and that effi- rious challenges for students with auditory pro- cacy measures are taken. cessing disorder (APD). These students, by the very nature of their disorder, are at risk for learning.The challenge of listening to degraded, Step 1: Determining the APD Profile reduced, or distorted speech in acoustically poor and Indicators environments may result in fatigue and auditory overload that causes the student to tune Whether the audiologist uses the Bellis-Ferre2,6 out or alternatively become distracted and ex- or the Buffalo Model7 profiles to describe the hibit annoying behaviors. When a student is student’s auditory processing strengths and diagnosed with APD, all too often the primary weaknesses and identify a profile type, it is im- or only recommendation offered is to fit a per- portant to not only consider the test results, sonal FM system.1,2 While this may be an ap- but also the case history, observational, and propriate management tool for some students qualitative test behavior information. The au- who exhibit an auditory input disorder, it should thor finds Auditory Decoding, Organization/ not be regarded as a routine recommendation, Output, and Tolerance-Fading Memory (TFM) for there are other critical factors to be consid- profiles to offer the strongest indications that a ered. In fact, the recommendation of a personal personal FM system would be an appropriate FM system must be considered as a part of the management strategy. Abnormal results on management process and not as the sole or pri- monaural low redundancy speech and dichotic mary management strategy. Unfortunately, while tests, that is, tasks involving degraded signals, the benefits of sound field amplification for all figure-ground, or speech in competition, strongly children, and particularly those at risk for lis- suggest that a personal FM system would be an tening and learning are well documented,3,4 appropriate strategy to modify the effects of little data have been published that demon- the classroom listening environment.1,8 strate the efficacy of personal FM amplifica- Table 1 provides a summary of quantita- tion as a management strategy for students tive and qualitative indicators for personal FM with APD.1,5 system use based on: (1) case history, observation checklist, and qualitative test behaviors; and (2) monaural low redundancy speech and MANAGEMENT OF APD dichotic test findings and auditory processes and skills tested. Table 2 summarizes APD The management of APD involves three pri- profiles that typically support the use of an FM mary areas—the listening environment, com- system as a management strategy. It is impor- pensatory strategies, and direct therapy for re- tant to note the contraindications for recom- mediation. Managing classroom acoustics and mending a personal FM system as a manage- the use of a personal FM system, both a part of ment tool when reviewing the APD profile. managing the listening environment, should be For instance, FM is seldom recommended for approached in a systematic manner. A suggested the student with a Prosodic deficit since the four-step management process includes: (1) primary difficulty is not related to the clarity of evaluating the student’s auditory processing the acoustic signal.6 Generally, an FM system strengths and weaknesses, determining the pri- would not be recommended for the student mary APD profile, and identifying APD pro- with an Integration deficit stemming from dif- file indicators that support or contraindicate ficulties synthesizing auditory information, al- the use of a personal FM system; (2) evaluating though it may be deemed appropriate insofar the acoustical classroom environment and rec- as it benefits the speech-in-noise deficits that ommending appropriate modifications; (3) se- also characterize this APD subtype.6,9 The stu- lecting and fitting the personal FM system dent with an Auditory Association deficit pro- that most appropriately meets the student’s file does not understand the auditory message CLASSROOM ACOUSTICS AND PERSONAL FM TECHNOLOGY/ROSENBERG 311 tic Sentence Index; ICM, Ipsilateral Compet- tic Sentence Index; eport, whereas they are binaural integration tests eport, whereas they significant response biases competing message (SSI-CCM) competing listening condition(s); speech measuresspeech with reverberation)competing message (SSI-ICM) signals/auditory closure degraded auditory signals Synthetic Sentence Identification with contralateral Synthetic (SSW)—peak in a Test Word Staggered Spondaic Binaural separation/binaural competition Binaural integration/binaural competition Time-compressed speech (both alone and Time-compressed speech Sentence Identification with ipsilateral Synthetic processing/auditory with performance Monaural auditory Temporal separation/auditory figure-ground group settings) (abnormal score/significant Tests Speech ear difference)Auditory Figure Ground SCAN: Monaural auditory separation/auditory figure-ground filtered and other low-pass Words SCAN: Filtered with degraded auditory Auditory performance complaint about the competition; attempt complaint about the competition; attempt the earphone with competition)to move Words* Competing Digits* Dichotic Binaural integration/binaural competition integration/binaural competition Binaural Case History, Observation Checklist, and Qualitative Test Behavior Indicators Case History, Behavior Checklist, Observation Test and Qualitative hear you.) hearing/listening in noise (Huh? I didn’t Complaint of difficulty the auditory for target similar sounding words Appears to mishear and substitutes repetition of information Requires speech in conversational discrimination of fine acoustic differences Poor deteriorate as auditory increases auditory listening behaviors overload fatigue; Excessive auditory noise/reverberation, chaos, with reduced redundancy (e.g., excessive listening in situations Difficulty directions following Difficulty of communication up with the flow keeping Difficulty languages learning foreign Difficulty responses Delayed IndicatorsTest APD RedundancyMonaural Low Speech-in-noise Test Digits can be considered as tests of binaural separation if the response task is a directed ear r and Dichotic Words *Competing Monaural auditory separation/auditory figure-ground Tested or Skills Processes Auditory Dichotic Tests (significant ear difference; (significant ear difference; Tests Dichotic Competing Sentences is used. when the free report response format Disorders; SSI, Synthe Auditory Processing for Test auditory processing disorder; SCAN, Screening APD, FM, frequency modulated; Test. Word Staggered Spondaic ing Message; CCM, Contralateral Competing SSW, Binaural separation/binaural competition Table 1Table Strategy APD Management as an Technology FM Suggesting Indicators and Qualitative Quantitative 312 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Table 2 Summary of APD Profile Indicators Suggesting FM Technology as a Management Strategy Profile Indicator APD Test Findings Selected Management Strategies

Auditory Poor auditory discrimination Assistive listening technology to improve S/N decoding Bilateral deficit on monaural low Bottom-up processing approach (aural profile redundancy speech tests rehabilitation therapy model) Bilateral deficit on dichotic speech tests Environmental modifications to improve signal clarity and redundancy Evidence of associated sequelae noted Activities to enhance auditory closure on case history, observation forms, Self-advocacy (listening strategies, and qualitative test behaviors self-management)

Output/ Deficit on any task requiring report of Assistive listening technology to improve S/N organization more than two critical elements Environmental modifications to enhance S/N profile (e.g., DDT, SSW, PPST, DPT) Break information into smaller units; provide May have poor speech-in-noise skills multi-step directions one at a time May exhibit reversals and ordering Strategies training for study skills, note taking, problems test taking, and use of external organizers May omit target or substitute (e.g., checklists, agenda book, calendar) previously heard word Organizational and metacognitive strategies Evidence of associated sequelae noted training to strengthen the memory trace on case history, observation forms, Highly structured, rules-based environment and qualitative test behaviors with consistent routines

Tolerance- SSW—LC peak, high/low order effect, Assistive listening device to improve the S/N fading low/high ear effect Improve classroom acoustics memory Phonemic synthesis—quick, impulsive Noise desensitization practice profile responses Flexible preferential seating Speech in noise—significant Quiet work/study area discrepancy from score in quiet Direct instruction to improve outlining and MLD—may be reduced notetaking skills Case history may reveal hyperacusis, Use of metalinguistic and metacognitive weak short-term memory, oral and strategies (e.g., rehearsal, chunking, written discourse errors, poor imagery, mnemonics) reading comprehension, phonemic Rule out attention deficit disorder breakdown FM, frequency modulated; APD, auditory processing disorder; DDT, Dichotic Digits Test; SSW, Staggered Spondaic Word Test; PPST, Pitch Pattern Sequence Test; DPT, Duration Pattern Test; S/N, signal-to-noise ratio; MLD, masking level difference.

as a result of a linguistic comprehension prob- term memory weaknesses, may benefit from a lem and as such a recommendation for a per- personal FM system as a management strategy, sonal FM system would not be indicated. but caution must be exercised in this case. The There is some question as to whether the Au- other important TFM management plan com- ditory Associative profile should actually be ponents, such as noise desensitization practice considered an APD subtype or perhaps more and compensatory strategies for auditory mem- appropriately classified as a language process- ory deficits must be fully implemented, rather ing impairment.10 Students who exhibit a true than relying exclusively on the improved sig- Tolerance-Fading Memory (TFM) profile, that nal-to-noise ratio offered by the FM system to is, significant difficulty understanding speech reduce the other symptoms of this specific APD under adverse listening conditions and short- profile. CLASSROOM ACOUSTICS AND PERSONAL FM TECHNOLOGY/ROSENBERG 313

Step 2: Classroom Acoustics Evaluation of FM technology as a management strat- and Modification egy.9 Ultimately, the findings of the classroom acoustics appraisal could result in specific mod- The synergistic effects of noise and reverbera- ifications or accommodations being included tion and the resulting degradation of speech in the student’s Individual Educational Plan perception, such as the masking of key elements (IEP) or 504 plan. In addition to modifying of speech, the smearing of temporal cues, and classroom acoustics, effective teaching strate- the loss of speech energy over distance, are well gies also should be suggested.9,12 known.11–14 These conditions place all students Evaluation and treatment of classroom at risk in their listening environments, espe- acoustics always should be done first. Only cially those with APD who have documenta- after this is accomplished should the audiolo- tion to support their difficulty processing de- gist move forward with fitting the personal graded or competing auditory stimuli. It requires FM system. There will be times during the considerable and focused effort for these stu- school day when the student may not use the dents to attend, listen, and process acoustic in- FM system, and at some point the student will formation under optimum listening conditions. need to transition from dependency on the as- Compromises in the quality of the acoustical sistive device as he/she learns to cope with the environment will undoubtedly impact the qual- environmental listening challenges by using ity of the student’s educational opportunities. strategies implemented as part of the manage- The acoustical environment is but one of the ment plan. For these reasons, it is imperative parameters that affect a student’s auditory pro- that classroom acoustics be assessed and im- cessing capabilities, although it is indeed a proved to the extent possible before or at least powerful factor in that it can modify acoustic concurrent with the fitting of the personal FM signals and produce reduced communication system. It is advisable to consider the acousti- opportunities in these primarily auditory- cal environment in the home, and offer man- verbal environments. Unfortunately, noise and agement recommendations for that environ- reverberation levels in classrooms have remained ment so that the student will be able to benefit relatively unchanged over the past 30 years.3,9,12 from a similar management plan in both lis- The Classroom Acoustics Working Group tening and learning environments. has developed a working draft of a standard for acoustics in school classrooms and other learning spaces that may be used as a guide to create Step 3: Personal FM Selection enhanced listening and learning environments and Fitting where students can receive more consistent auditory signals.15 A variety of materials in the An audiologist must evaluate students with school and classroom environments can absorb APD for whom a personal FM system has been sounds and decrease the effects of noise and re- recommended.9,20,21 When a personal FM sys- verberation on speech perception. A summary tem has been recommended as a management of acoustical modifications for the classroom strategy for a student with APD, members of are shown in Table 3. Sound and noise control the Individual Education Plan (IEP) team are in the classroom and school environment is required under the Individuals with Disabilities both a science and an art, and information on Education (IDEA) to consider assistive tech- specific acoustical modifications may be found nology, which it defines as any item, piece of in comprehensive resources.9,12–14 Audiologists equipment, or product system that is used to have the knowledge and skills to measure class- increase, maintain, or improve the functional room noise and reverberation levels using a capabilities of a child with a disability. This re- systematic method and the appropriate instru- quirement uses stronger language than that in- mentation.12 Use of an observational checklist cluded prior to the 1997 IDEA amendments. may be beneficial and it could serve as the pre- Local education agencies (LEA) that do not liminary measure for studying the effectiveness provide audiological services, either directly or 314 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Table 3 Summary of Management Strategies to Improve Classroom Acoustics Classroom Environment Management Strategy

Ceilings Optimal ceiling height for listening environment: 9–12 feet Suspended acoustical tile ceiling or installation of other absorbent material to control reverberation if the ceiling height exceeds 12 feet Sound absorption material in the plenum space if suspended ceiling is shared by another classroom Acoustical ceiling tile with sound absorption coefficient sufficient to achieve desired noise and/or reverberation reduction Suspended banners, student work, and hanging plants Floors Carpeting installed over pad of adequate thickness to reduce noise and reverberation Extend carpeting onto the bottom portion of wall surfaces Alternatives: rubberized or resilient tile with an acoustical underlayment and/or strategically placed area rugs or carpeting Regular carpet maintenance to enhance indoor air quality and diminish allergic effects Windows Double-pane windows Cloth draperies without rubberized backing Closed windows Walls and Doors Acoustical panels placed on non-parallel, partially down the wall Cork bulletin boards, felt or flannel boards, and acoustical or fabric-covered wall surfaces Solid core-door Well-fitting doors with noise lock seal, gasket, or felt treatment Cover vents in doors or insert a filter Seating and Furniture Staggered desk and table arrangement Arrangement Felt or rubber caps, or tennis balls on chair and table legs Main instruction area away from noise sources Furniture arrangement to accommodate the teacher’s instructional style Avoid open plan rooms Heating, Ventilation, Acoustical duct lining for supply and return ducts and Air Conditioning Regular maintenance of HVAC systems (HVAC) Systems Noise control devices in HVAC systems (e.g., duct silencers, adequate duct length, vibration isolators, adequate duct and diffuser sizes) Lighting Change fluorescent light ballasts on regular basis to avoid hum House lighting above acoustical tile ceiling Special Purpose Areas Location away from high noise sources Mobile bulletin boards and bookcases placed at angles to walls to decrease reverberation Study carrels lined with acoustic tiles or rubber pads

contractually, place themselves at risk if they dent-specific factors to be considered in the se- fail to engage the services of an audiologist in lection and fitting process that must be the re- the FM evaluation, selection, and fitting pro- sponsibility of an audiologist. cess. In addition to the fact that a mild gain When recommending a personal FM sys- amplification device is being recommended for tem, the audiologist and the multidisciplinary a student with normal hearing, there are stu- team should consider the unique benefits of CLASSROOM ACOUSTICS AND PERSONAL FM TECHNOLOGY/ROSENBERG 315

Table 4 Considerations in Selecting and Fitting Personal FM Systems for APD Management Personal FM Components Consideratio

Receiver options Body worn Self-contained ear level Portable desktop Transmitter/microphone Microphone quality Directional microphone Noise canceling microphone Microphone style (boom, lapel, collar) Team teaching options Mute switch Coupling options Headset (earphone, walkman, stethoclip) Earbud (monaural or binaural) Special applications (open earmold, retention devices) Attenuation capabilities (headset or ear level receiver) Small and large group applications Team teaching or pass microphone option Desktop application

this technology to improve the signal-to-noise greater responsibility as the manager of his/her ratio and decrease the effects of noise, rever- listening environment, although the student beration, and distance from the speaker. Table may require specific training in self-advocacy 4 lists the factors to be considered in the selec- strategies and assertiveness training to reach tion and fitting of a student with APD with a this level of sophistication.20 personal FM system. The available options are the wired body-worn systems, wireless self- contained receivers, and the portable desktop Step 4: Inservice Training and receiver. Special attention should be given to Efficacy Measures microphone options to ensure that critical speech components are delivered to the listener A structured trial evaluation period will allow while maintaining the highest possible acous- the multidisciplinary team to determine if the tic signal quality. The audiologist, again as part personal FM system is an effective management of the multidisciplinary management team, strategy for a specific student. Florida’s Technical should consider the age of the student, the Assistance Report on Auditory Processing Dis- classroom or particular applications and settings order proposes a model for the trial evaluation where the device will be used, the student’s period and includes a detailed framework for the motivation to use the technology, the responsi- inservice training component.7 Important con- bility level of the student, and the ease of use siderations in the trial evaluation period are: and maintenance of the various systems in making the recommendation for a specific type • assessment of the classroom (or other) listen- of device. Careful attention to each of the se- ing environment, perhaps using a tool such lection and fitting options should allow for the as the Listening Environment Profile9,22 or a personal FM system to be used as a tool to en- worksheet or computerized program avail- hance the effectiveness of other management able from some FM manufacturers; strategies. The personal FM system should not • completion of a pre-trial observation form, such be considered as the device that is capable of as the Screening Instrument for Targeting Edu- solving all of the student’s educational and com- cational Risk (SIFTER),23 the Fisher’s Audi- municative problems.1,8,9,16 The personal FM tory Problems Checklist,24 or the Children’s system should enable the student to assume Auditory Performance Scale (CHAPS)25; 316 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

• inservice training for the classroom teacher, mendation as an effective management strat- student, and parent or other professionals as egy. Due to the limited research supporting the appropriate1,9; efficacy of personal FM for students with APD, • completion of a post-trial observation form audiologists remain challenged to contribute by the classroom teacher and the parent9; to the research base to support the continued • completion of post-trial evaluation form by recommendation of this assistive hearing tech- the classroom teacher, parent, and student9; nology. • plan for monitoring use and maintenance of the FM system9; and • periodic audiologic reevaluation to monitor ABBREVIATIONS hearing sensitivity and assess functional listening skills.1,26 APD auditory processing disorder CHAPS Children’s Auditory Perception of The evaluation trial period should extend Speech for at least six weeks in order to adequately de- FM frequency modulated termine if this management strategy produces SIFTER Screening Instrument for Targeting positive behavioral, communicative, and edu- Educational Risk cational changes. The student, as well as the TFM Tolerance-Fading Memory parent and the teacher, should provide input during the post-evaluation trial measurements. If the recommendation is to continue use of REFERENCES the personal FM system, careful, ongoing documentation of efficacy is encouraged. Eventu- 1. Bellis T. Central Auditory Processing Disorders in ally the goal should be to train the student to the Educational Setting: From Science to Practice. San Diego, CA: Singular; 1996 depend less upon the FM system and to imple- 2. Stein R. Application of FM technology to the ment the other strategies he/she has mastered management of central auditory processing disor- in order to attend, listen, learn, and self-manage ders. In: Masters M, Stecker N, Katz J, eds. Central auditory processing challenges in various lis- Auditory Processing Disorders: Mostly Manage- tening environments. Audiologists may wish to ment. Needham Heights, MA: Allyn & Bacon; compile pre- and post-trial evaluation data in 1998:89–102 order to support the efficacy of this manage- 3. Rosenberg G, Blake-Rahter P,Heavner J, et al. Im- ment strategy.1,8–10 proving classroom acoustics (ICA): a three-year FM sound field classroom amplification study. J Ed Audiol 1999;7:8–28 4. Rosenberg G. FM sound field research identifies CONCLUSIONS benefits for students and teachers. Ed Audiol Rev 1998;15 (3):6–8 Assisting in the management of the acoustical 5. Stach B, Loiselle L, Jerger J, Mintz S, Taylor C. classroom environment and the appropriate Clinical experience with personal FM assisting listening devices. Hear J 1987;5:1–6 recommendation, fitting, and monitoring of per- 6. Bellis T, Ferre J. Multidimensional approach to the sonal FM technologies for students with APD differential diagnosis of central auditory processing are among the responsibilities of the audiolo- disorders in children. J Am Acad Audiol 1999;10: gist as a member of the multidisciplinary team. 319–328 Careful attention to classroom acoustics must 7. Florida Department of Education. Central audi- be the first consideration, followed by recom- tory processing disorders: technical assistance paper. mendation of the personal assistive listening Tallahassee, FL: Author; 2001 8. Stecker N. Overview and update of CAPD. In: device only if it is indicated by the student’s Masters M, Stecker N, Katz J, eds. Central Audi- profile of auditory processing strengths and tory Processing Disorders: Mostly Management. weaknesses. Systematic fitting and monitoring Needham Heights, MA: Allyn & Bacon; 1998:1–14 of the personal FM system is indicated in 9. Hall J, Mueller H. Audiologists Desk Reference, order to determine the efficacy of this recom- vol. 1. San Diego, CA: Singular; 1997 CLASSROOM ACOUSTICS AND PERSONAL FM TECHNOLOGY/ROSENBERG 317

10. Bellis T. Subprofiles of central auditory processing ment in schools. Lang Speech Hear Serv School disorders. Ed Audiol Rev 1999;16(2):4–9 2000;31:376–384 11. Smaldino J, Crandell C. Speech perception in the 18. Improving Classroom Acoustics: Inservice Train- classroom. In: Crandell C, Smaldino J, eds. Class- ing Manual. Tallahassee, FL: Florida Department room Acoustics: Understanding Barriers to Learn- of Education; 1995 ing. The Volta Rev 2001; 101:15–21 19. Educational Audiology Association. FAQs about 12. Crandell C, Smaldino J. Room acoustics for listeners classroom acoustics. Ed Audiol Review 2000;17:8–9 with normal-hearing and hearing impairment. In: 20. Chermak GD, Musiek FE. Central Auditory Pro- Valente M, Hosford-Dunn H, Roeser R, eds. Audi- cessing Disorders: New Perspectives. San Diego, ology: Treatment. New York: Thieme; 2000:601–623 CA: Singular; 1997 13. Finitzo-Hieber T, Tillman T. Room acoustic ef- 21. ASHA. Guidelines for fitting and monitoring FM fects on monosyllabic word discrimination ability systems. ASHA Desk Reference. Rockville, MD: for normal hearing and hearing impaired children. ASHA; 2000 J Speech Hear Res 1978;21:440–458 22. Cockburn J. Listening Environment Profile. Peta- 14. Nelson, P, Soli, S. Acoustical barriers to learning: luma, CA: Phonic Ear, Inc.; 1995 children at risk in every classroom. Lang Speech 23. Anderson K. Screening Instrument for Targeting Hear Serv School 2000;31:356–361 Educational Risk (S.I.F.T.E.R.). Tampa, FL: Edu- 15. Classroom Acoustics Working Group. Improving cational Audiology Association; 1989 acoustics in American schools: working draft of 24. Fisher L. Fisher’s Auditory Problems Checklist. standard. Lang Speech Hear Serv School 2000;31: Tampa, FL: Ed Aud Assn; 1976 391–393 25. Smoski W, Brunt M, Tannahill J. Children’s Audi- 16. Crandell C, Smaldino J. Acoustical modifications tory Performance Scale. Tampa, FL: Ed Aud Assn; for the classroom. In: Crandell C, Smaldino J, eds. 1998 Classroom Acoustics: Understanding Barriers to 26. Johnson C, Von Almen P.The functional listening Learning. The Volta Rev 2001;101:33–46 evaluation. In: Johnson C, Benson P, Seaton J, eds. 17. Sieben G, Gold M, Sieben G, Ermann, M. Ten Educational Audiology Handbook. San Diego. ways to provide a high-quality acoustical environ- CA: Singular; 1996:336–339

Managing Children’s Central Auditory Processing Deficits in the Real World: What Teachers and Parents Want to Know

Jeanane M. Ferre, Ph.D.1

ABSTRACT

A diagnosis of (central) auditory processing disorder has been made. What do you tell the child’s teacher(s) regarding management of the disorder’s effects in the classroom? How do you get the parents to understand and become involved in the management process? This article describes environmental modifications and curriculum-based compensations for specific types of central auditory processing deficits (CAPD) as well as common games and everyday activities that can improve auditory and auditory-related skills to create long-term benefit for children with CAPD.

KEYWORDS: Central auditory processing, management, environmental modifications

Learning Outcomes: Upon reading this article, the reader will be able to (1) list at least five specific management strategies appropriate for various types of CAPD, (2) list at least five common games or activities that have remedial benefit for various types of CAPD, and (3) describe the use of assistive technology for students with CAPD.

The practical importance of making a correct of any kind is to allow appropriate manage- diagnosis is that children having different types of ment to be devised. This is true with respect to problems vary significantly in their needs and un- children’s central auditory processing deficits less a differential diagnosis is made, their poten- (CAPD). As Myklebust1 eloquently pointed tialities are lost. out, “unless a differential diagnosis is made, H. Myklebust, 1954 [children’s] potentialities are lost because different types of problems will result in different These words, written nearly 50 years ago, language-learning-listening needs.” are still true today. It generally is accepted that The converse is equally true. That is, chil- a key reason for conducting diagnostic testing dren presenting with similar language-learning-

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Jeanane M. Ferre, Ph.D., Private Practice, 1010 Lake Street, Suite 111, Oak Park, IL 60301. E-mail: [email protected]. 1Private Practice, Oak Park, Illinois. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,319,326,ftx,en;sih00225x. 319 320 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

listening needs may do so for different reasons. 263–276, respectively) for a discussion of direct Two children may each be poor at following di- remediation approaches, and to Baran (pages rections in the classroom and both may present 327–336) for a discussion of management ap- with diagnosed (central) auditory processing dis- proaches with older children and adults. order. However, we need to manage the poor direction following of each one differently, depending upon the type of central auditory deficit SPECIFIC CENTRAL AUDITORY identified through diagnostic testing. As more PROCESSING DEFICITS remediation programs appear on the market, all promising to improve an array of processing The Bellis-Ferre model4 delineates five types of and related skills, it is obvious that specifying CAPD based on key central auditory test find- the nature of CAPD is important in choosing ings, and describes typical behavioral manifes- the right remediation. tations associated with each deficit. The model Direct therapeutic remediation is one third describes three primary central auditory deficits of the management equation. Like a tripod that characterized by presumed underlying site of cannot stand without all three legs, effective dysfunction. Two secondary deficit types are in- management of children’s CAPD requires the cluded that, while yielding unique patterns of inclusion of appropriate environmental modi- results on central auditory tests, may be appro- fications and compensatory strategies. It is no priately described as manifestations of more longer acceptable to make blanket recommen- supramodal or cognitive-linguistic disorder. For dations such as “reduce extraneous noise, sit near a detailed discussion of these deficits, the reader the front of the room, or repeat and rephrase to is referred to the article by Bellis (this issue, improve signal quality” for each and every child pages 287–296). For the purposes of this dis- presenting with CAPD. Just as we choose a cussion, the deficits are described briefly here. therapy program that appears to be a best fit, Auditory decoding deficit is characterized these seemingly straightforward recommenda- by poor discrimination of fine acoustic dif- tions for everyday management must be turned ferences in speech with behavioral characteris- on their ear and made more specific based on tics similar to those observed among children the diagnostic information obtained through the with peripheral hearing loss. Auditory decod- central auditory evaluation. Parents and teaching deficit can create secondary difficulties in ers need to know how to provide daily inter- communication (e.g., vocabulary, syntax, seman- vention. This kind of intervention does not tics, and/or second language acquisition) and/or refer to the individualized pull-out sessions with academic skills (e.g., reading decoding, spell- the speech-language pathologist or educational ing, notetaking, and/or direction following). specialist. Rather, it is intervention that com- Integration deficit likely is due to ineffi- plements the efforts of specialists and is on- cient interhemispheric communication and is going throughout the day, at school, and at characterized by deficiency in the ability to home. These are strategies that parents and perform tasks that require intersensory and/or teachers can use to modify the way they talk to multisensory communication. The child does and with our children, that help them choose not synthesize information well, may complain the games they play, and/or set up classrooms that there is too much information, and has to enable all children to meet their potential. difficulty intuiting task demands, starting com- This article focuses on common environ- plex tasks, transitioning from task to task, or mental modifications and curriculum-based completing tasks in a timely fashion. Impact on compensations for specific types of CAPD. communication is variable, and academic diffi- Common games and everyday activities useful culties in reading, spelling, writing, and other for improving auditory and auditory-related integrative tasks are typically observed. processing skills are suggested. The reader is Prosodic deficit is characterized by defi- referred to other publications,2,3 as well as to ciency in using prosodic features of a target, a Chermak and Musiek, and to Musiek, Shinn, predominantly right hemisphere function. The and Hare (this issue, pages 297–308 and pages child displays difficulty in auditory pattern MANAGING CHILDREN’S CAPD/FERRE 321 recognition, which is important for perceiving mediation. Direct remediation seeks to improve running speech, and may have difficulty recog- deficient skills and to teach additional compen- nizing and using other sensory patterns (e.g., satory/ coping strategies. Environmental modi- visual, tactile). Difficulties are observed with fications and use of compensatory strategies pragmatic language (e.g., reading facial expres- minimize the impact of the deficit on everyday sions, body language, gestures; recognizing or functions. The environmental modifications and using sarcasm or heteronyms), rhythm percep- compensatory strategies discussed here focus tion, music, and nonverbal learning. on the impact of noise, changes in oral message Auditory associative deficit, a secondary presentation (e.g., repetition and rephrasing), CAPD subtype, is characterized by significant classroom seating and use of visual cues, and auditory-language processing difficulties. Chil- modifications to the curriculum including pre- dren with this deficit do not intuit the rules of viewing and scheduling. language as well as theirs peers. While normal processors too often do not think outside the box, these children rarely are in the box; the box being Impact of Extraneous Noise those rules of language, both explicit and im- plicit, that we use to get the message. They may A listener’s ability to function in background exhibit specific language impairments in syntax, noise depends on: (1) the type of noise present, vocabulary, semantics, verbal and/or written ex- (2) the loudness of the noise relative to the tar- pression, pragmatics, or social communication. get, and (3) task demands.5 Any listener will More importantly, though, they exhibit func- benefit from reduction of extraneous noise in tional communication deficits even in the ab- the listening environment. The specific impact sence of specific language impairment. A key of noise and management of a noisy environ- behavioral characteristic is a finding of adequate ment depends on the central auditory deficit academic performance in early elementary identified. grades with increasing difficulty as linguistic de- Children with auditory decoding deficit mands increase in upper grades. This child may tend to perform more poorly as noise increases present with sub-average to sub-normal intel- relative to the target and when the background lectual potential when assessed using standard noise is more similar to the target. The gymna- (language-biased) intelligence tests. sium, lunchroom, and playgrounds are areas Output-organization deficit is another of particular difficulty. For this child, it is im- secondary subtype showing a unique pattern on perative that excessively loud and/or highly re- central auditory processing tests. This deficit is verberant noise be minimized either through characterized by difficulty in performing tasks direct signal enhancement or noise abatement requiring efficient motor path transmission/ techniques. motor planning and may be a behavioral mani- Direct signal enhancement can be achieved festation of impaired efferent function or plan- through the use of assistive listening devices ning/executive function deficit. Behaviorally, (ALD) in which the signal-to-noise ratio (SNR) the child may be disorganized, impulsive, and a reaching the child’s ear is improved. Unlike poor planner/problem solver. Difficulties in traditional amplification where the speech sig- expressive language, articulation, and syntactic nal and any ambient noise may both be ampli- skills may be observed as well as educational fied, the physical configuration of the personal problems in direction following, note-taking, ALD has the effect of pulling the target signal and remembering assignments. away from the noise via very mild gain amplification, thereby pushing the noise further into the perceptual background. This results in a CAPD MANAGEMENT ISSUES significantly more favorable SNR and, in turn, improved speech reception. Likewise, sound- As noted previously, effective management of field FM (i.e., frequency modulated) systems CAPD requires environmental modifications, enhance the target signal for groups of chil- use of compensatory strategies, and direct re- dren. When used with proper diagnosis and 322 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

monitoring, a personal ALD can improve au- use noise-reducing earplugs while studying to ditory attention, short term memory, auditory attenuate background school and household discrimination and perception6–9 and would be noise. Conversely, many children with integra- appropriate for a child with auditory decoding tion deficits benefit from listening to music or deficit.10,11 other steady-state signals as a way to mask ran- Recommended classroom SNR should ex- dom, aperiodic noises that may disrupt con- ceed +15 dB with reverberation time of less centration. than 0.4 seconds.12 Classroom noise abatement The child with output-organization deficit can be accomplished by carpeting rooms, using generally has difficulty filtering out distrac- curtains, drapes and/or acoustic ceiling tiles, tions of any kind, not just auditory noise. Envi- placement of baffles within the listening space, ronments that are visually and/or auditorily eliminating open classrooms, or damping highly chaotic are especially difficult for this child. reflective surfaces. Placing bookcases perpen- This child may benefit from use of an ALD or dicular to each other or creating a 6–8 inch from noise desensitization activities to improve space between side-by-side bookcases can cre- tolerance and filtering abilities. The reader is ate baffles and minimize noise. Cork bulletin referred to Ferre11 and Garstecki15 for a further boards and the use of fabric to cover hard sur- discussion of noise desensitization. For a child faces increases sound absorption and dampens with associative deficit, background noise may reflective surfaces. Felt pads on the bottoms of be no more bothersome than for normal proces- chair and table legs minimize furniture-to-floor sors, provided the child understands the mes- noise. For a discussion of classroom acoustics sage and the rules. One recent client could do and FM technology, see the articles by Rosen- repetitive, soccer practice drills without any berg (this issue, pages 309–318), as well other thought to the background noise; however, he publications.13,14 complained that it was too noisy when involved In contrast to the child with auditory de- in a real soccer match in the same environ- coding deficit where SNR is central to im- ment. For him, soccer practice was easy to un- proved performance, children with integration derstand and not very demanding; however, he and prosodic deficits are bothered by noise— was overwhelmed by the constantly changing not as a function of its level, but as a function demands of a real soccer game and could not of the task demands. While performing simple tolerate the game’s attendant noise. Like the tasks with which they are highly familiar, noise child with integration deficit, the noise level is of little consequence; however, in a test-taking was not central to his difficulties and direct or study situation with its increased multisen- signal enhancement (e.g., ALD) was not rec- sory demands, even simple random noises such ommended. Instead, intervention focused on as coughing, pencil sharpening, or a ringing improving his ability to understand the rules of telephone may be intrusive and too loud. Be- the game as opposed to the rules of a practice. cause of the nature of the deficit, ALDs are Other noise management techniques for the usually not beneficial. Instead, in these situa- child with associative deficit involve improving tions, the task demands should be altered, the the signal’s linguistic clarity rather than its child should be removed from the environ- acoustic clarity. Linguistic clarity is discussed ment, or a way found to mask the random every- below. day noises that intrude. Taking frequent breaks while studying, extending test or project completion time, and reducing assignment size can Changes In Oral Message Presentation lessen potential processing overload, thereby improving tolerance for noise. Use of separate Altering message presentation typically has in- rooms for test taking, study carrels, and smaller volved recommendations to speak more slowly class size also would reduce the noise that may to the child or to repeat or rephrase informa- undermine the listener’s processing. Consider- tion. While all are reasonable, each carries a ation should be given to having these children codicil. It often is not necessary to actually MANAGING CHILDREN’S CAPD/FERRE 323 slow down one’s speech to enhance it. Rather, ing experience. For the child with auditory de- altering the timing, pacing, emphasis and pars- coding deficit, the addition of visual cues is ing of the message can enhance the salience of important and the child should be encouraged the key parts. These modifications benefit stu- to look and listen and may be taught lipreading/ dents with auditory decoding or prosodic deficit. speechreading skills. However, for the child In addition, speaking more slowly will be a whose ability to integrate auditory and visual natural consequence of greater articulatory pre- information is compromised (integration defi- cision. Repetition of the signal is most helpful cit), the addition of visual cues may create fur- if the repeated message is enhanced or empha- ther confusion. For this child, the look and lis- sized in some fashion, spoken with greater pre- ten rule should be modified to look or listen.10,11 cision, or accompanied by a related visual or In the classroom, children are asked to copy tactile cue (e.g., pointing, gesture). material from a board or screen while simulta- For the child with an associative deficit, neously listening to related information. In repetition rarely produces an improvement in these situations, allow the child with integra- understanding. For these students, rephrasing— tion or output-organization difficulties to look by offering the listener a more familiar tar- then listen (i.e., sequential processing) in order get—is the method of choice when the mes- to minimize potential overload on his or her sage has been misunderstood linguistically. In synthesis and/or organization skills.10,11 For addition, this child requires the use of explicit other children, classroom seating is of less im- language when given commands or asked ques- portance than the method of presentation. The tions. The ambiguous sit still should be replaced child with a prosodic deficit requires an ani- with keep your hands (or feet, or head) still.For mated teacher with a melodic voice who uses this child, it is essential that we say what we multisensory techniques to make the point.For mean and mean what we say. To gauge the child’s the child with an associative deficit, additional understanding, replace “do you understand?” visual cues may take the form of notes written with “tell me what you think I said.” That is, ask in margins, highlighted text, diagrams, or other the child to paraphrase instructions or state- visual aids that help the child to visualize the ments rather than repeating them verbatim. concept or that make the message more ex- Target rephrasing is counterproductive if plicit and familiar. The child with organiza- the processing deficit is related to issues of in- tional difficulties may need outlines or check- tegration (i.e., how quickly and efficiently the lists to assist planning and recall skills. target was synthesized) or output (i.e., how efficiently targets were organized). For these listeners, rephrasing adds additional perceptual Modifications to the Curriculum targets rather than enhancing signal clarity. Rephrasing to these children is confusing as it Pre-teaching or previewing material is de- gives them too much information to which to signed to enhance familiarity with the target. listen and to organize. For these children, we For any listener, the more familiar one is with must remember two simple rules: (1) keep it the target, the easier the processing becomes. short and simple (KISS), and (2) don’t say it; Books on tape, copies of teachers’ notes/texts, show me. Cliffs Notes™ (Hungry Minds, Inc.), seeing movies, and reading aloud to children can enhance their familiarity with the subject, task Use of Visual Cues and Preferential demands, main ideas, key elements, and vocab- Classroom Seating ulary. For children with integration, associative, prosodic, or output-organization deficit, In preferential seating, an effort is made to knowledge of the rules, structure, and task de- maximize both the acoustic and visual aspects mands up front will minimize overload. How- of the target based on the presumption that the ever, it is important to note that for these chil- addition of visual cues will enhance the listen- dren this knowledge is not acquired through 324 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

mere exposure, but through explicit instruc- in) rather than those with more open-ended tion, repeated practice, and review across a va- questions (e.g., essays) are preferred for these riety of contexts and settings. children. For children with integration or out- Many children with CAPD, regardless of put-organization deficit, it may be necessary to specific type, report experiencing excessive au- allow them to write in a test booklet rather than ditory fatigue. Scheduling breaks in the listen- transfer answers to a score sheet, especially for ing day helps to minimize this reported audi- standardized testing. Because of its impact on tory overload. For example, do not schedule a language skills, associative deficit may result in a reading lesson right after an English grammar child performing below his or her potential on lesson. Intersperse lecture classes with activi- many tests, especially standard language-biased ties that are more hands-on or less academi- IQ tests. Non-language biased instruments (e.g., cally challenging (e.g., physical education). Do Test of Nonverbal Intelligence or Leiter Perfor- not schedule homework or therapy immedi- mance Inventory) should be used to gain a more ately after school. Instead schedule some min- reliable estimate of the child’s potential. For utes of downtime following school. other tests, it may be necessary to read the ques- When determining particular courses or tions to the student to ensure understanding. curricular requirements, the presence of a CAPD should be considered. Students with decoding deficit should consider a nonverbal alternative Management Issues Summary for foreign language requirements. Many states not only recognize American Sign Language Children with auditory decoding deficit bene- as a foreign language, but also accept it for fit from modifications and compensations that credit at the high school and collegiate levels.16 focus on improving the quality and access to Children with associative deficit should be the acoustic signal (e.g., repetition, preferential granted a waiver or substitution (e.g., a culture seating, noise abatement, and use of ALD or course) for a foreign language requirement due tape recorder). Children with integration deficit to the nature of their auditory-language diffi- who do not synthesize information as quickly culties. Because children with integration or and efficiently as other children benefit from prosodic deficit are deficient in their ability to modifications and compensations that adjust intuit multisensory or unisensory patterns, the the quantity and structure of the signal (e.g., foreign language chosen should minimize the repetition with related cues, short and simple demands on these skills. Rather than a nonver- instructions, pre-teaching material, untimed and bal language, consider Hebrew or Latin as a closed set tests, highly structured second lan- second language for these children. These language). Children with associative deficit do not guages are highly structured and well ordered. speak the same language as their peers and re- In addition, they tend to be read-only languages, quire modifications and compensations that at least at the elementary and secondary levels. transform the signal to improve comprehension Finally, regardless of the second language cho- (e.g., rephrasing, use of unambiguous language, sen for students with output-organization defi- pre-teaching rules and vocabulary, second lan- cit, we should consider and minimize any po- guage substitution or waiver, non-language test tential adverse impact on their expressive speech instruments). Children with prosodic deficit and language (i.e., verbal and written), recall, have difficulty recognizing and attaching mean- and planning skills by allowing dictated re- ing to auditory patterns and benefit from mod- sponses on written exams, and minimizing oral ifications that improve both the structure and language exams. meaning of the signal (e.g., repetition with em- Children with integration, associative, pro- phasis, knowledge of rules, untimed activities, sodic, or output-organization deficit should highly structured second language). Finally, avoid timed tests, as these underestimate true students with output-organization deficit have knowledge and skills. In general, tests with difficulty organizing information. These chil- closed-set questions (i.e., multiple choice or fill- dren benefit from modifications and compen- MANAGING CHILDREN’S CAPD/FERRE 325 sations that enhance signal salience (e.g., use of Wheel of Fortune®§, anagrams or scrambled ALDs, note-taking service, pre-teaching rules words, change-a-letter games (e.g., turn the word and outlines, closed-set tests) and assist output back into the word soak by changing one letter at a skills (e.g., oral responses for written exams, time), or words-in-a-word game (e.g., make ten extended time tests). words out of the letters in the word cafeteria).

THE GAMES WE PLAY SUMMARY

Like their nonimpaired peers, everyday games Children with CAPD have a variety of prob- and activities can enhance the auditory and re- lems and vary significantly in their educational, lated processing skills of children with CAPD. communicative, and psychosocial needs. It is For improved auditory decoding and general important to differentially diagnose the prob- listening skills, the child should be involved in lem to understand those particular needs. It also activities that teach or require active listening is essential that we as clinicians differentially or discrimination and analysis for success. Com- manage those needs not only in our choices for mon games and activities include: telephone remediation, but also in the ways we change game, rhyming games, start-stop games (e.g., the environment to minimize the adverse ef- Red Light- Green Light), identification of same- fects of the deficit and in how we assist the different, or sound recognition games (e.g., the child in compensating for his or her deficits. child says a word that begins with the last sound By making recommendations more deficit- of your word: caT – Tack, doG – Gum). specific and infusing this deficit-specificity into For improved integration, prosody, or or- everyday activities throughout the entire day, ganizational skills games and activities that re- we can minimize the adverse effects of these quire synthesis (e.g., parts-to-whole), pattern deficits on the child’s life and ensure that po- recognition, increase in complexity or speed of tentialities are not lost. response, or require verbal mediation for success should be used. Examples include name that tune, feely bag (e.g., place several common ob- ABBREVIATIONS jects in a bag, the child names or describes the objects through touch only), Scrabble®, Bog- ALD assistive listening devices gle®, UpWords®, Rummikub®, Bopit®, Bopit CAPD central auditory processing deficits Extreme®, Brain Warp®, Simon®*, simon says, FM frequency modulated card games, chess, karate, dance, singing, dra- SNR signal-to-noise ratio matic arts, and gymnastics. For improved associative or output skills, activities that encourage out of the box thinking, REFERENCES build vocabulary, enhance use of linguistic rules or concepts, and improve problem-solving skills 1. Myklebust H. Auditory Disorders in Children. should be used. Common games in this area New York: Grune & Stratton; 1954 2. Masters G, Stecker N, Katz J, eds. Central Audi- include Catch Phrase®, Scattergories®, Up- tory Processing Disorders: Mostly Management. Words®, Taboo®, Clever Endeavor®, alphabetiz- Boston, MA: Allyn & Bacon; 1998 ing games, rebus puzzles, word puzzles (e.g., Plexers™), Password®, Boggle®, Scrabble®,

§Clever Endeavor is a registered trademark of Mind Games, Inc.; Plexers is a registered trademark of Plexers, *Boggle, Scattergories, Simon, Scrabble, Bopit, Bopit Ex- Inc.; Password is a registered trademark of Mark Good- treme, Catch Phrase, Brain Warp, Taboo, and UpWords are son Productions, LLC.; Wheel of Fortune is a registered registered trademarks of Hasbro, Inc.; Rummikub is a trademark of Merv Griffin Enterprises, LLC.; all other registered trademark of Pressman Toy Corporation. games listed are registered trademarks of Hasbro, Inc. 326 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

3. Ferre J. Behavioral therapeutic approaches for cen- 10. Bellis T. Assessment and Management of Central tral auditory problems. In: Katz J, ed. Handbook of Auditory Processing Disorders in the Educational Clinical Audiology, 5th ed. Philadelphia, PA: Lip- Setting. San Diego, CA: Singular; 1996 pincott Williams & Wilkins; 2002:525–531 11. Ferre J. Processing Power: A Guide to CAPD As- 4. Bellis T,Ferre J. Multidimensional approach to dif- sessment and Management. San Antonio, TX: The ferential diagnosis of central auditory processing Psychological Corp; 1997 disorders in children. J Am Acad Audiol 1999;10: 12. American Speech Language Hearing Association. 319–328 Guidelines for acoustics in educational environ- 5. Crandell C, Smaldino J. Room acoustics and audi- ments. ASHA 1995:37(Suppl 14) tory rehabilitation technology. In: Katz J, ed. Hand- 13. Stein R. Application of FM technology to the book of Clinical Audiology, 5th ed. Philadelphia, management of central auditory processing disor- PA: Lippincott Williams & Wilkins; 2002:607–630 ders. In: Masters G, Stecker N, Katz J, eds. Central 6. Shapiro A, Mistal G. ITE-aid auditory training for Auditory Processing Disorders: Mostly Manage- reading and spelling-disabled children: clinical case ment. Boston, MA: Allyn & Bacon; 1998:89–102 studies. Hear J 1985;38:14–16 14. Crandell C, Smaldino J. Sound field amplification 7. Shapiro A, Mistal G. ITE-aid auditory training for in the classroom: applied & theoretical issues. In: reading and spelling-disabled children: a longitu- Bess F, Gravel J, Tharpe A, eds. Amplification for dinal study of matched groups. Hear J 1986;39: Children with Auditory Deficits. Nashville, TN: 14–16 Bill Wilkerson Center Press; 1996:229–250 8. Stach B, Loiselle L, Jerger J, Mintz S, Taylor C. 15. Garstecki D. Auditory-visual training paradigm Clinical experience with personal FM assistive lis- for hearing-impaired adults. J Acad Rehab Audiol; tening devices. Hear J 1987;40:24–30 1981;14:223–238 9. Blake R, Field B, Foster C, Plott F, Wertz P.Effect 16. National Information Center on Deafness. States of FM auditory trainers on attending behaviors of that Recognize American Sign Language as a For- learning-disabled children. Lang Speech Hear Serv eign Language. Washington, DC: Gallaudet Uni- School 1991;22:111–114 versity, Author; 2001 Managing Auditory Processing Disorders in Adolescents and Adults

Jane A. Baran, Ph.D.1

ABSTRACT

This article provides an overview of the nature of auditory processing disorders (APD) in adolescents and adults and provides a framework for professionals working with patients across the lifespan. Three major approaches to the management of the patient with APD are discussed, with emphasis placed on those approaches that incorporate both ecological and context-specific perspectives in the management of the adolescent and adult with APD. Also discussed are implications of APD for the fitting of hearing aids and other amplification devices in patients with comorbid peripheral hearing losses.

KEYWORDS: Auditory processing disorder, adolescents and adults, rehabilitation

Learning Outcomes: Upon completion of this article, the reader will be able to (1) identify the major approaches to the management of auditory processing disorders in adolescents and adults, and (2) discuss the implications of a comorbid auditory processing disorder when fitting hearing aids and other amplification devices to patients with peripheral hearing losses.

The diagnosis of auditory processing dis- processing deficits observed in patients with orders (APD) has received considerable atten- both developmental and acquired APD.3–6 More tion in both the clinical and research arenas recently, efforts have been directed toward the since the mid 1950s, when Bocca and his col- development of management programs to meet leagues reported the results of their landmark the needs of these individuals.4,5,7–14 investigation of the auditory deficits associated A review of the literature in this area re- with temporal lobe compromise.1,2 Since that veals that most of the efforts directed toward time, considerable attention has been directed the development of management procedures toward defining the nature and the extent of the and programs for APD have focused on the re-

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Jane A. Baran, Ph.D., Department of Communication Disorders, University of Massachusetts, 715 North Pleasant Street, Amherst, MA 01003–9304. E-mail: [email protected]. 1Department of Communication Disorders, University of Massachusetts, Amherst, Massachusetts. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,327,336,ftx,en;sih00226x. 327 328 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

habilitative needs of children, with consider- needed to deal with these difficulties in the ab- ably less attention being paid to the develop- sence of a specific diagnosis, (3) individuals with ment of management programs specifically de- APD associated with confirmed compromise signed to meet the needs of the older patient of the central auditory nervous system (CANS), with APD.7 This situation is presumed to be and (4) older individuals who are experiencing related to a number of factors. Most notable normal degenerative processes associated with among these factors is the large increase in the aging. Many of these individuals, especially number of children with language and learning those in the first two groups, will have devel- problems who have been referred for APD oped compensatory strategies that served them assessments, and who subsequently have been well when they were younger; however, as they diagnosed as having APD over the past two matured into adulthood, some of these indi- decades. With the increase in the number of viduals will have found that the strategies that children diagnosed with APD has come pres- proved to be useful when they were younger sure to develop efficacious management pro- failed to meet their needs as adults. As chil- grams to serve the needs of this population. dren, these individuals would have been con- The more recent desire to turn our attention to figured within an ecological system as learners the rehabilitative needs of the adolescent and and they would have been defined relative to adult with APD has been motivated by two their cognitive and learning abilities. As adults, factors. First, the school-aged children who their ecological systems expand and their audi- were identified as having APD in the last dec- tory deficits become apparent across multiple ade or two are now maturing into adolescents settings (e.g., employment, leisure, family, com- and adults with APD; and second, with an munity life).15 The older individual is no longer increased awareness of APD on the part of defined primarily on the basis of his or her per- the public, many previously undiagnosed adults formance in school. Contexts and environ- with APD are seeking evaluation, and as a re- ments change as do communicative demands sult, are being diagnosed with this disorder. and as a result the adult with APD may face This growing number of older individuals with new challenges that will vary across time and confirmed APD presents new challenges for context. those professionals who are responsible for designing management programs to meet their needs. COMORBIDITY

Although APD may exist in isolation, it is PATIENT CHARACTERISTICS often the case that the patient with APD also experiences one or more additional comorbid In attempting to serve the needs of adolescents conditions. These comorbid conditions may in- and adults with APD, the audiologist is likely clude speech and language disorders, learning to encounter four groups of patients. These in- disabilities, attention deficit disorders with or clude (1) individuals who were identified at an without hyperactivity, psychological disorders, early age with APD and who received some emotional disorders, frank neurological involve- type of intervention for these auditory deficits ment of the CANS, and peripheral hearing in the past, (2) individuals who present for the loss.To date, there have been numerous attempts first time as adults with significant auditory to establish cause and affect relationships be- complaints in the absence of other significant tween each of these disorders and APD; how- findings—many of these individuals may have ever, these efforts have failed to elucidate the had difficulties in the past that were addressed exact nature of these relationships—which are by teachers and/or parents who were able to by nature complex, interrelated, and not neces- provide the individualized attention and care sarily unidirectional. Also, a consideration of MANAGING APD IN ADOLESCENTS AND ADULTS/BARAN 329

Table 1 Common Presenting MANAGEMENT APPROACHES Symptomatology Associated with Auditory Processing Disorders and Related Disorders in Adolescents and Adults Management approaches used to remediate or alleviate the auditory deficits associated with Inordinate difficulty hearing in noisy or reverberant APD can be categorized into three major cate- environments gories. These approaches are designed to accom- Lack of music appreciation plish the following goals: (1) to improve signal Difficulty following conversations on the telephone quality, (2) to improve the individual’s auditory Difficulty following multi-step directions/instructions perceptual skills, and (3) to enhance the individ- Difficulty taking notes during lectures ual’s language and cognitive skills.16 An alterna- Difficulty following long conversations tive classification system divides the procedures Difficulty learning a foreign language into two categories based on the nature of the Difficulty learning technical or discipline-specific mechanisms that underlie the processing require- vocabulary where the language is largely ments involved. In this classification system, the unfamiliar or novel approaches would be classified as either bottom- Difficulty in directing, sustaining, or dividing up (i.e., stimulus-driven) or top-down (i.e., con- attention cept-driven) procedures.5 Bottom-up procedures Auditory memory deficits would encompass those approaches designed to Spelling difficulties facilitate the individual’s ability to receive and Reading difficulties process the acoustic signal, whereas top-down Organizational problems approaches would involve those procedures that Behavioral, psychological and/or social problems are designed to facilitate the interpretation of au- Academic or vocational difficulties ditory information according to linguistic rules and conventions and other available sensory information. Although there is not necessarily a the presenting symptomatology associated with one-to-one fit, for the most part approaches that APD and many of these comorbid disorders re- are designed to improve the signal quality or to veals that a number of behavioral symptoms improve the individual’s auditory perceptual skills are shared by several of these disorders (Table 1). would be classified as bottom-up or stimulus- Although the establishment of cause and driven procedures, whereas approaches that are effect relationships among these disorders may used to enhance the individual’s linguistic and be desirable from a differential diagnostic per- cognitive skills would be classified as top-down spective, what is more critical to the successful or concept-driven procedures. management of the individual with comorbid Although many of the management op- conditions is the identification of these co- tions used with children can and have been used existing deficits and problems. Once these defi- with older individuals, adolescents and adults cits are uncovered, a comprehensive manage- with APD often present unique challenges and ment plan can be developed that will address special needs. Brain plasticity, that is optimal all areas of weakness. Moreover, since the be- during childhood, is less amenable to signifi- havioral deficits associated with some of these cant alternation in the older individual.5,7 Hence, disorders may negatively affect the efficacy of a there may be less reliance on formal and infor- particular APD approach for a given patient, it mal approaches specifically designed to im- is important that a comprehensive, and prefer- prove the individual’s auditory perceptual skills ably interdisciplinary, assessment of the individ- when the individual in need of services is older. ual’s auditory, linguistic, cognitive, academic and In these cases, rehabilitative efforts are more vocational functioning be undertaken before likely to focus on the other two management an APD management plan is developed when- strategies (i.e., improving the signal quality and ever deficits or problems are anticipated in any enhancing the individual’s cognitive and lin- of these areas. guistic resources). In addition, academic, voca- 330 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Table 2 Examples of Academic Modifications transdisciplinary approach to management of for Students in Secondary and Postsecondary APD is recommended. Academic Placements

Test administration in alternative environments (e.g., less noise, fewer distractions) Provision of notetaking services Auditory Training Provision of tutoring services (may include peer tutoring) Auditory training (AT) approaches can involve Reduced course loads both formal and informal techniques directed Creative scheduling of classes to ensure that course at improving the individual’s auditory percep- requirements and task demands are equally tual skills. Selection of the specific type of AT distributed over the course of the academic should be informed by a comprehensive central program auditory assessment through which the spe- Preferential seating (if seating is assigned) cific auditory deficit areas can be identified and Tape recordings of lectures and presentations then targeted for remediation. Musiek and his Video recordings of lectures and presentations colleagues have identified a number of audi- Assignment or selection of course section where tory processes that can be assessed using a instructor’s teaching philosophy and style are number of different central auditory tests and consistent with student’s needs they have outlined specific management proce- Provision of outlines, lecture notes, or reading dures that can be used to address each deficit assignments prior to class presentation so that the area.10,11 Information on these procedures as student can review materials in advance well as a discussion of other issues and consid- Other accommodations to address comorbid- erations in the selection of formal and informal learning difficulties (e.g., untimed tests, alternative auditory training procedures can be found in test formats) these resources. The reader is referred to Musiek, Shinn, and Hare, and to Chermak and Musiek (this issue, pages 263–276, and pages 297–308, respectively) for additional discus- tional, psychological and emotional issues often sions of AT. surface and/or become more severe as the individual with APD matures and as auditory processing demands increase in new and varied listening contexts. Individuals who have met Signal Enhancement Approaches with success as a result of previous intervention efforts may now find that strategies that served Signal enhancement procedures involve the use them well in earlier years fail to provide them of specialized equipment, environmental modi- with the assistance needed to face the challenges fications and speaker training. Approaches in- they experience as adolescents and young adults. clude the provision of either a personal FM Additional management options, such as aca- (frequency-modulated) system or a classroom/ demic or vocational modifications (Table 2), group amplification system, reduction of extra- psychological counseling, career counseling, and neous or competing environmental noise, pref- transition planning must be entertained. Hence, erential seating, enhancing the presentation of there are a number of additional issues and the message though a variety of means (e.g., use considerations that need to be addressed when of clear speech17–19), and use of specialized tech- planning a management program for adoles- nology (e.g., telephone amplifiers). All of these cents and adults. Some of these may be appro- approaches can be used at home, at school, or on priately managed by the audiologist, whereas the job, with appropriate modifications.4,7,9–14,20 other services may be more efficiently provided For additional discussions of personal FM sys- by other professionals in related areas. As was tems and classroom modifications, the reader is the case for assessment, an interdisciplinary or referred to the articles by Rosenberg and by MANAGING APD IN ADOLESCENTS AND ADULTS/BARAN 331

Ferre, (this issue, pages 309–318, and pages should be deficit-specific and tailored to meet 319–326, respectively). the unique learning and communication circumstances and needs of the patient. Older students and adults need to function in a number of different contexts with varying commu- Linguistic and Cognitive Interventions nicative demands and they typically do not enjoy the same level of support that is provided As the individual matures into adolescence and to young children. There may be no Individu- then adulthood, interventions are less likely to alized Education Plan (IEP) team, advocate, or focus on specific skill acquisition (e.g., phono- parent to inform others of the difficulties that logical awareness training) and more likely to the individual is experiencing. Moreover, as the focus on the development of metalinguistic child moves from an elementary school place- and metacognitive skills. Many well-conceived ment into a middle school, junior high, and strategies have been developed and used with high school placement, he or she is likely to be individuals with APD. Specific information on working with more adults in more contexts. these procedures can be found in a number of The student in the upper grades is expected to sources and will not be detailed here.4,7–13 The move from classroom to classroom to meet reader also is referred to Bellis (this issue, pages with teachers who have expertise in particular 287–296) for additional discussions of met- subject matters. With each different subject alinguistic and metacognitive approaches. comes a different teacher with his or her own Although many of the strategies that have teaching style—which may be conducive to the been recommended in the literature appear to child’s learning and communication needs, or be obvious and therefore should require little may prove to be at odds with the child’s learn- instruction other than identification of the strating style. Not only will the teaching style egy, this may in fact not be the case. If the strat- change, so will the environment within which egies were obvious to the individual with APD, the student must function. Depending on the then it is likely that this individual would have acoustics of the classroom, its location relative adopted the use of the strategy without the to noise sources both inside and outside of the need for specific instruction. Moreover, even if school building, and the size and composition the individual adopted a strategy that worked of the class, the student with APD may meet well for a given situation or context in the past, with more or less favorable listening environ- but did not learn how to generalize the strategy ments as he or she moves through the day. to new situations, the individual would con- These issues loom even larger when the indi- tinue to meet with communicative failure in vidual moves from a secondary educational pro- new contexts. In light of these comments, a for- gram to a postsecondary or technical school malized strategy instruction procedure should environment. In these settings, classes are gen- be given serious consideration for incorporation erally much larger and instructors often do not into any management plan developed for ado- have the opportunity to get to know each stu- lescents and adults with APD.7 dent’s learning style and needs, at least not in a timely manner. Moreover, the student may not have an individual who can serve as an advo- ECOLOGICAL PERSPECTIVES cate on his or her behalf. Therefore, it is important that the individual assume responsibil- Auditory problems are complex and the man- ity for his or her listening success. He or she ner in which they affect daily life are varied. needs to become a self-advocate and addition- Although individualized management plans are ally needs to become strategic. The simple ap- indicated for all patients with APD, they are plication of a strategy that the student learned especially important for adolescents and adults as a younger student may not be of assistance with APD. Management procedures selected in each new context. The older student must be for incorporation into a management plan able to evaluate each new listening situation, 332 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

identify possible strategies to compensate for als with an APD or related disorder is self- any processing difficulties that might be en- advocacy training. countered in the novel listening environment, select the strategy that appears to be the best alternative given the circumstances, and find Self-Advocacy Training another alternative if the selected strategy fails to meet the individual’s needs in this particular As individuals mature from childhood to ado- context. In other words, adolescents and adults lescence and into adulthood, the likelihood that with APD need to not only know a strategy, they will have a case manager, advocate, or but they need to become strategic. What worked other professional to advocate for their needs in one environment may not prove to be useful becomes increasingly smaller. Young students in another environment. often become dependent on these individuals to advocate on their behalf because these needs are provided for the students through their IEPs. As a consequence, many young students Career Counseling and do not develop the skills and abilities needed to Transition Planning take on this role as the need arises. They may struggle in new and difficult situations rather Career counseling and transition planning is than ask for assistance and reasonable accom- an often overlooked but essential component modations. This is particularly true at the post- of a management plan for the older student secondary level, where many students may feel with APD. Many adolescents and young adults that faculty are unapproachable, or that the do not fully appreciate how their learning and faculty will be biased against them if they dis- communication problems may interact with close their disorders or deficits. Without train- job demands. This lack of understanding may ing in self-advocacy skills, the postsecondary set them up for future frustration, possible fail- student may not be equipped to access the ac- ure, and loss of self-esteem as they enter the commodations needed to ensure success. job market. Some of this may be avoided if stu- Although problems related to poor devel- dents are provided guidance in this area opment of self-advocacy skills often are en- through the use of appropriate counseling ser- countered in postsecondary environments, they vices. Students who can identify their strengths may be equally as problematic for the em- and weaknesses and explore the variety of ca- ployee. Employees with APD who are not able reer options that are open to them will be more to advocate for their own needs may find that likely to choose a career where they can meet they are at risk for job loss or lack of advance- with reasonable success. Often parental or so- ment or promotion due to perceived employee cietal pressures push students into career ineffectiveness. These individuals also may find choices for which they are ill equipped, unin- that they are not accepted by colleagues in the terested, and unmotivated. Counseling may workplace, as they are perceived by co-workers help the student learn how to deal with these as aloof or antisocial. societal pressures and how to become more self-assertive. Even when a good match is found be- MANAGEMENT OF THE PATIENT tween an individual’s interests, skills, and career WITH APD AND PERIPHERAL or educational choices, it is likely that individ- HEARING LOSS uals with APD will encounter new problems as they move from one context to another. Explo- The discussion thus far has focused on interven- rations of the potential difficulties that may be tion programs and procedures designed for use encountered will help individuals with APD with the individual who has APD in the absence plan how they will react to these difficulties if of any involvement of the peripheral hearing they are encountered. Finally, an essential com- system. However, many individuals will present ponent of the management plan for individu- with an APD that either co-exists with, or is MANAGING APD IN ADOLESCENTS AND ADULTS/BARAN 333 secondary to, a peripheral hearing loss. More- monaural fittings for the two ears in spite of the over, it is anticipated that the number of patients finding of symmetrical pure tone hearing sensi- presenting with concomitant peripheral and cen- tivity during pure tone assessments. Even more tral auditory system involvement will continue interesting, however, was the finding that the to grow as medical advances increase life ex- binaural test condition resulted in significantly pectancy and the baby boomers continue to age. poorer performance when this score was com- The need for careful determination of the pared to the aided speech recognition score of presence of a comorbid APD is critical to the the better ear. successful management of the patient with pe- These same investigators obtained middle ripheral hearing loss. Many of the interventions latency responses for three of the original four outlined above can be used to alleviate the audi- patients under three conditions: monaural right, tory problems that these individuals experience. monaural left, and binaural presentation. Simi- However, this group of individuals presents lar patterns of performance were noted in that unique challenges to the audiologist responsible the morphologies of the waveforms derived for the selection and fitting of amplification. under the binaural presentation condition were Current preferred practice patterns require as- noticeably poorer than the morphologies of the sessment of the auditory periphery prior to the waveforms derived from the better ear in each fitting of amplification; however, the assessment case.26 For these patients, the presentation of of the integrity and function of the CANS in pa- auditory information to the second or poorer tients with peripheral loss being seen for fitting ear seemed to interfere with the processing of of amplification has received little attention.23,24 information presented to the better ear. Al- Most, if not all, patients presenting with though the exact mechanisms underlying this hearing loss are considered to be viable candi- phenomenon are not understood, it is likely dates for amplification given the advances that that some type of distortion is being introduced have occurred in hearing aid technology over by the peripheral and/or central system. An ob- the past several years. In addition, since the vious implication of these findings is that the benefits of binaural amplification have been es- binaural processes must work appropriately if a tablished, binaural fittings have become the patient fitted with hearing aids is to make opti- standard of care even in many cases with asym- mal use of binaural amplification. metrical hearing loss.25 In spite of the obvious Other researchers have demonstrated pa- benefits of binaural fittings for many if not the tient profiles that lend additional support to the majority of cases with peripheral hearing loss, importance of considering the status of the there exists a group of individuals for whom CANS when fitting patients with peripheral binaural amplification may be contraindicated. hearing loss who may be at-risk for CANS in- There are few professionals that would chal- volvement. Musiek and Baran24 outlined four lenge the benefits of binaural amplification in different case profiles where binaural amplifi- patients with symmetrical hearing losses. How- cation may be contraindicated based on the ever, as we learn more about the functioning of findings of a CANS compromise. Binaural am- the CANS and the potential for less than opti- plification may be contraindicated if: (1) sym- mal binaural processing associated with some metrical hearing loss is present, but the central CANS disorders, it is questionable whether the auditory test performance of one ear is markedly finding of a symmetrical peripheral hearing loss poorer than that of the other ear; (2) an asym- is sufficient evidence to justify a binaural fitting metrical hearing loss is present, and the central in these patients. For instance, Jerger and his auditory test performance of the better ear is sig- colleagues provided evidence of binaural inter- nificantly poorer than that of the poorer ear; (3) ference in four patients with symmetrical hear- a symmetrical hearing loss is present and abnor- ing losses.26 Aided speech recognition scores mal middle and/or late potentials are noted over were derived for three of these four patients one hemisphere versus the other (i.e., a signifi- under three test conditions: aided right ear, cant electrode effect); and (4) a symmetrical aided left ear, and binaural fitting. In each case, hearing loss is present and an ear effect is noted obvious differences were noted between the on electrophysiological testing. 334 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

These cases, taken together with those to meet the unique needs of each individual. identified by Jerger and his colleagues26 dem- Furthermore, these programs need to be closely onstrate instances of less-than-optimal binau- monitored and systematically evaluated, and the ral processing in some patients with peripheral individual’s management plan should be modi- hearing loss. To take advantage of binaural am- fied if the results do not show adequate prog- plification, all of the binaural processes must ress or if the patient’s context changes. work appropriately, including those that are mediated in the brainstem and the auditory cortex. Because the function of the binaural REFERENCES processes of the CANS are not adequately addressed by routine peripheral assessments, it is 1. Bocca E, Calearo, C, Cassinari V. A new method important that the audiologist consider the for testing hearing in temporal lobe tumors. Acta need to assess auditory processing when work- Otolaryngol 1954;44:219–221 ing with patients with peripheral hearing loss. 2. Bocca E, Calearo C, Cassinari V, Migliavacca F. Given the profiles outlined above, the in- Testing “cortical” hearing in temporal lobe tumors. Acta Otolaryngol 1955;45:289–304 clusion of an auditory processing assessment in 3. Baran JA, Musiek FE. Behavioral assessment of the hearing aid selection and fitting procedure the central auditory nervous system. In: Musiek for patients with peripheral hearing loss should FE, Rintelmann WF, eds. Contemporary Perspec- be given serious consideration, particularly tives in Hearing Assessment. Boston, MA: Allyn when evaluating a patient with known CANS & Bacon; 1999:375–413 involvement (e.g., a stroke, etc.) or one who 4. Bellis TJ. Assessment and Management of Central may be considered at-risk for an APD even in Auditory processing Disorders in the Educational the absence of a confirmed neurological factor Setting: From Science to Practice. San Diego, CA: Singular; 1996 (i.e., the elderly patient with severe auditory 5. Chermak GA, Musiek FE. Central Auditory Pro- comprehension difficulties, etc.). Recommended cessing Disorders: New Perspectives. San Diego, procedures include, but are not limited to, di- CA: Singular; 1997 chotic speech testing (e.g., dichotic digits) and 6. Musiek FE, Baran JA, Pinheiro ML. Neuroaudiol- a comparison of aided speech recognition scores ogy: Case Studies. San Diego, CA: Singular; 1994 obtained with monaural right, monaural left, 7. Baran JA. Management of adolescents and adults and binaural fittings.24,26,27 In many cases, ad- with central auditory processing disorders. In: Mas- ters GA, Stecker NA, Katz J, eds. Central Auditory ditional behavioral and electrophysiologic tests Processing Disorders: Mostly Management. Boston, 23,24 may be warranted. Decisions regarding the MA: Allyn & Bacon; 1998:195–214 inclusion of any of these procedures should be 8. Chermak GA. Metacognitive approaches to man- based on a consideration of the patient’s pre- aging central auditory processing disorders. In: senting complaints and the existence of other Masters GA, Stecker NA, Katz J, eds. Central Au- comorbid medical conditions.23,24 Alternative ditory Processing Disorders: Mostly Management. procedures for incorporating such assessments Boston, MA: Allyn & Bacon; 1998:49–62 into the evaluation protocol for patients who 9. Chermak GA, Musiek FE. Managing central auditory processing disorders in children and youth. are being seen for hearing aid selection and fit- Am J Acad Audiol 1992;1:62–65 ting procedures can be found in Musiek and 10. Musiek FE. Habilitation and management of audi- Baran.24 tory processing disorders: overview of selected procedures. J Am Acad Audiol 1999;10:329–342 11. Musiek FE, Baran JA, Schochat E. Selected man- CONCLUDING COMMENTS agement approaches to central auditory processing disorders. Scand Audiol 1999;28(Suppl 51):63–76 Auditory processing disorders (APD) represent 12. Musiek FE, Schochat E. Auditory training and central auditory processing disorders. Semin Hear a complex and heterogeneous group of disor- 1998;19:357–365 ders. No single approach will address the needs 13. Masters GA, Stecker NA, Katz J, eds. Central Au- of each individual who presents with APD. ditory Processing Disorders: Mostly Management. Management programs must be individualized Boston, MA: Allyn & Bacon; 1998 MANAGING APD IN ADOLESCENTS AND ADULTS/BARAN 335

14. Stein R. Application of FM technology to man- 20. Ray H, Sarff LS, Glassford JE. Sound field ampli- agement of central auditory processing disorders. fication: an innovative educational intervention for In: Masters GA, Stecker NA, Katz J, eds. Central mainstreamed learning disabled students. The Di- Auditory Processing Disorders: Mostly Manage- rective Teacher 1984; Summer/Fall:18–20 ment. Boston, MA: Allyn & Bacon;1998;89–92 21. Bender WA. Learning Disabilities: Characteristics, 15. Kleinman SN, Bashir AS. Adults with language- Identification, and Teaching Strategies. 2nd ed. learning disabilities: new challenges and changing Boston, MA: Allyn & Bacon; 1995 perspectives. Semin Hear 1996;17:201–216 22. Hallahan DP, Kauffman JM, Lloyd JW. Introduc- 16. American Speech-Language-Hearing Association. tion to Learning Disabilities. Boston, MA: Allyn Central auditory processing: current status of re- & Bacon; 1996 search and implications for practice. Am J Audiol 23. American Speech-Language-Hearing Association. 1996; 5:41–54 Preferred Practice Patterns for the Profession of 17. Picheny MA, Durlach, NI, Briada LD. Speaking Audiology. Rockville, MD: Author; 1997 clearly for the hard of hearing I. Intelligibility dif- 24. Musiek FE, Baran JA. Amplification and the cen- ferences between clear and conversational speech. J tral auditory nervous system. In: Valente M, ed. Speech Hear Res 1985;28:96–103 Hearing Aids: Standards, Options, and Limita- 18. Picheny MA, Durlach, NI, Briada LD. Speaking tions. New York: Thieme; 1996:407–437 clearly for the hard of hearing II. Acoustic charac- 25. Dillon H. Hearing Aids. New York: Thieme; 2001 teristics of clear and conversational speech. J 26. Jerger, J, Silman, S, Lew HL, Chmiel R. Case stud- Speech Hear Res 1986;29:434–436 ies in binaural interference: converging evidence 19. Picheny MA, Durlach, NI, Briada LD. Speaking from behavioral and electrophysiologic measures. J clearly for the hard of hearing III. Attempt to de- Am Acad Audiol 1993;4:122–131 termine the contribution of speaking rate to differ- 27. Strouse Carter A, Noe CM, Wilson RH. Listeners ences in intelligibility between clear and conversa- who prefer monaural to binaural hearing aids. J Am tional speech. J Speech Hear Res 1989;32:600–603 Acad Audiol 2001;12:261–272

Reliable Differential Diagnosis and Effective Management of Auditory Processing and Attention Deficit Hyperactivity Disorders

Warren D. Keller, Ph.D.,1 and Kim L. Tillery, Ph.D.2

ABSTRACT

Children with Attention Deficit Hyperactivity Disorder (ADHD) manifest behaviors strikingly similar to children with Auditory Processing Disorders (APD). Recent research suggests that these two disorders are often co-morbid, but can occur independently. The appropriate management of ADHD and APD is dependent upon a reliable and valid diagnosis using multiple sources of information and measures. The most effective evidence based approaches for these two disorders are reviewed with an emphasis on the importance of differential diagnosis.

KEYWORDS: Attention deficit, hyperactivity, auditory processing, central nervous system stimulant medication

Learning Outcomes: Upon completion of this article, the reader will understand (1) the assessment strategies and techniques that should be employed in order to accurately differentially diagnose ADHD and APD; (2) the lack of evidenced-based treatment approaches regarding the management of these two disorders; and (3) that ADHD and APD are two separate disorders, necessitating an interdisciplinary evaluation by both the audiologist and psychologist.

Children behave similarly for a variety of orders, constitute a heterogeneous group with reasons and it is imperative that we remember many co-morbid conditions, and present with that all that is hyper is not hyperactivity and all strikingly similar symptoms of inattention, dis- that is poor listening is not auditory processing tractibility, hyperactivity, and poor listening dysfunction. Children with attention disorders, skills. The appropriate management of a child as well as children with auditory processing dis- necessitates accurate differential diagnosis.

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Kim L. Tillery, Ph.D., Assistant Professor, State University of New York College at Fredonia, Department of Speech Pathology and Audiology, Thompson Hall, Fredonia, NY 14063. E-mail: [email protected]. 1Neuropsychologist, Independent Practice, East Amherst Psychology Group, East Amherst, New York; 2Assistant Professor, State University of New York College at Fredonia, Department of Speech Pathology and Audiology, Fredonia, New York. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,337,348,ftx,en;sih00227x. 337 338 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

ATTENTION DEFICIT creased chronic otitis media.6 As young adults, HYPERACTIVITY DISORDER those with ADHD are at great risk for the development of alcoholism, substance abuse, and In the early 1900s, the complex of symptoms, anti-social behaviors.1 now commonly referred to as hyperactivity, was There is increasing evidence that children regarded as being a flaw in moral character. Ter- exhibiting ADHD are experiencing an under minology has changed as our knowledge of the arousal of the central nervous system (CNS) disorder has improved.1 Currently, the Diagnos- and hence, many clinicians and researchers tic and Statistical Manual (DSM-IV)2 describes refer to ADHD as an arousal disorder. Lou and ADHD as: 1) hyperactive-impulsive (ADHD- colleagues found a hypoperfusion of blood flow HI), 2) predominantly inattentive (ADHD-PI), to the frontal area of the brain in children with and 3) combined (ADHD-C) types. ADHD.7 Zametkin and colleagues found re- ADHD is one of the most common child- ductions in glucose metabolism in the premotor hood problems referred to child treatment cen- cortex and superior prefrontal cortex in individ- ters, and is believed to comprise approximately uals diagnosed with ADHD, these areas of the 40 % of referrals.1 It is characterized by an in- brain being implicated in the control of atten- ability to sustain attention, motoric hyperactiv- tion and motor activity.8 Clinically, we see neu- ity, and impulsivity inappropriate to the child’s ropsychological tests of executive functions that chronological age.2 There is typically an exac- are sensitive to frontal lobe behaviors, such as erbation of symptoms in situations where phys- the Category Test,9and the Wisconsin Card ical movement is restrained or where sustained Sort Test,10 being helpful in differentiating inattention is required, such as in classroom situ- dividuals with ADHD from other disorders. ations. Barkley describes the child with ADHD as having difficulty inhibiting and following rule-governed behaviors.1 The difficulties that children with ADHD ADHD-PI TYPE OR APD? experience are cross situational in nature, occurring at home, in school, with peers, and in The diagnostic classification of attention disor- most social situations.1 This is a chronic devel- ders in children is divided into two types— opmental disorder that most often is not out- ADHD-HI and ADHD-PI. This distinction grown.1 Children with ADHD present with a has occurred from the time diagnostic classifica- variety of secondary features that may be help- tion began to emphasize attention as opposed ful in making an accurate diagnosis and are to mere hyperkinetic behavior.11 The child with often the focus of treatment. A substantial por- ADHD-PI subtype differs in many ways from tion of children with ADHD will manifest co- the child with ADHD-C subtype. ADHD-PI morbid learning disorders.1 It is believed that children are more likely to experience internal- 25 to 40 % of those with ADHD will experi- izing symptoms as opposed to the disruptive be- ence specific learning disabilities that will ad- havior that characterizes hyperactive children. If versely impact their academic achievement.1 anything, they present with hypoactivity as op- Of the remaining children, 90 % will under- posed to hyperactivity. The gender ratio is less achieve in school given their intellectual poten- imbalanced among the ADHD-PI subtype. tial.1 In addition, children with ADHD present Girls more frequently fall into the ADHD-PI with a variety of socioemotional disturbances, subtype than the ADHD-C or ADHD-HI sub- and are often disliked by their peers.3 types.12 The differences between the two groups Associated features of individuals with are such that some have even argued that they ADHD include higher rates of noncompliance, represent two separate disorders, and should be an increased rate of minor physical anomalies,4 conceptualized as distinct and unrelated.12 The difficulty mastering bladder and bowel con- extent to which children with ADHD-PI sub- trol,5 disruption in sleep/wake cycles,1 and in- type may be manifesting APD that is respon- DIAGNOSIS AND MANAGEMENT OF APD AND ADHD/KELLER, TILLERY 339 sible for their primarily inattentive symptoms culty that involve anterior cerebral areas.13,18 needs to be investigated. Weak expressive language and poor handwrit- ing are not listening problems, but are associated anatomically with TFM—the motor plan- AUDITORY PROCESSING ning region of the frontal lobe—which is the DISORDERS same cortical area that Zametkin implicates with ADHD.8 Broca’s area (inferior frontal re- Individuals with APD do not effectively use gion) is associated with expressive language and auditory information, often have difficulty in both motor programming of articulatory move- understanding complex and lengthy directions, ments and writing functions are regulated by require repetition with directions, and may ap- the pre-motor area of the frontal lobes.13–15 pear to have a peripheral hearing loss.13 The misinterpretation of speech signals may be due to a variety of APD problems, better defined in Organization specific subtypes. The reader is referred to other publications for the method to diagnose these While Decoding and TFM types of APD are specific subtypes13–16and to Bellis (this issue, seen in isolation or in combination with each pages 287–296). other, the Organization subtype is not usually seen by itself.13,19 Organization type of APD is termed an Output-Organization Deficit14 and Decoding is diagnosed when significant corrupted auditory sequencing or planning is noted and the Weak phonemic awareness, known as decod- child displays difficulty with sequential infor- ing type of APD13or termed Auditory Closure mation and is disorganized at home or in (Decoding),14 is the most common type of school.13–15 The pre- and post- central gyri, APD.13–15 Besides discrimination errors, poor and anterior temporal areas may be responsible decoding ability also is manifested by difficulty for these auditory behaviors.13,15,17 in manipulating sounds, resulting in poor ability to blend sounds together. Such errors may reflect the child’s faulty mental perception of Integration the sounds, resulting in poor reading, spelling and word finding abilities and difficulty in ac- A final subtype of APD is Integration or curately understanding what is said. The left Integration Deficit.13–16 Poor inter-hemispheric posterior temporal area is responsible for audi- function (via the corpus callosum) may underlie tory processing and receptive language func- this subtype given the left ear deficit on dichotic tions, thus giving rise to the poor receptive lan- tests that require language response.14 Charac- guage skills commonly associated with clients teristics include long delays in response to audi- who are poor decoders.13–15,17 tory stimuli, poor reading, spelling, writing, and use of language skills.13–15,19

Tolerance-Fading Memory APD SUBTYPES SEEN IN ADHD Signs of frontal and anterior temporal involvement are consistent with the second most com- Subtyping APD may serve an important role in mon type of APD, the Tolerance-Fading Mem- the differential diagnosis of APD, ADHD, as ory (TFM) subtype.13 A small region of the well as specific learning disorders. Although parietal lobe (post central gyrus) also may be some researchers caution that APD subtypes associated with TFM, giving rise to short-term have yet to be validated,20,21 our research and memory limitations and speech-in-noise diffi- clinical work involves an exploration as to how 340 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

the subtypes may be instrumental in differential COMPREHENSIVE ASSESSMENT diagnosis, recommending appropriate referrals OF ADHD and providing effective remediation strategies. A published study investigating APD sub- Comprehensive assessment of children with types among the population of those diag- ADHD has been almost as controversial among nosed with APD and ADHD found a high mental health clinicians as has the proper assess- percentage of children with TFM APD.16 This ment of children with APD has been among au- also was observed in the children who partici- diologists. While there are those clinicians who pated in the Tillery et al study,22 where 80% of have argued that ADHD can be effectively and the children presented with TFM APD and properly diagnosed using only standardized be- 55% were found to exhibit significant reversals, havioral questionnaires and a comprehensive his- thereby showing an Organization (APD) Defi- tory, clinically elevated scores on these standard- cit. It is not surprising that TFM is associated ized behavioral report measures only indicate the with ADHD, given its association with ante- presence of ADHD symptomatology, but tell us rior temporal functions and the proximity to nothing about the cause of these behaviors. the frontal area associated with ADHD.8,13 Colegrove and colleagues,26 among others, Clinically, it has been noted that reversals may found that the use of behavioral questionnaires be more common in ADHD. It has been our alone are not particularly useful in the differen- practice to refer children for psychological eval- tial diagnosis of ADHD, and propose that the uation to rule out ADHD when these APD use of questionnaires alone may lead to improper subtypes have been found. diagnosis. Others have argued that in order to reduce the over identification of childhood ADHD and to make an accurate diagnosis, it is CO-MORBIDITY OF ADHD AND APD necessary to approach the assessment in a comprehensive fashion that includes continuous per- Increasingly, research suggests that ADHD and formance tests, standardized normed behavioral APD are two separate disorders that can occur measures, neuropsychologic and psycho-educa- independently or co-morbidly.22 Table 1 sum- tional assessments, measures of memory func- marizes the results of the studies that investi- tioning, a comprehensive medical and develop- gated the relationship between these two disor- mental history, as well as an assessment of ders.22–25 Varying criteria for the assessment of socio-emotional and personality factors in order ADHD make interpretation questionable. These to rule out disorders such as anxiety which so methodologic assessment issues hamper the va- often mimics ADHD.26,27 It is our position that lidity of much of the ADHD literature. in order to provide effective management, an as-

Table 1 Summary of Studies Evaluating Co-Morbidity of ADHD and APD, and Indicating the Criteria Used to Diagnosis ADHD Study APD in ADHD Cases ADHD in APD Cases

Gascon et al23** 15 / 19 with APD (79%) Cook et al24** 12 / 15 with APD (80%) Riccio et al.25* 15 / 30 with ADHD (50%) Tillery et al.22*** 36 / 66 with APD (55%) 19 / 66 mild APD (29%) ADHD was diagnosis by: *teacher and parental ratings on behavioral questionnaires; **physician / DSM III-R; and ***comprehensive psychological evaluation / DSM-IV/ Clinical titration of Ritalin®. DIAGNOSIS AND MANAGEMENT OF APD AND ADHD/KELLER, TILLERY 341 sessment of ADHD must include all of the ceiving Ritalin.22 While a significant medica- above as well as consideration as to whether an tion effect was not found in the APD test per- APD itself may be responsible for behavioral formance, there was a significant medication symptomatology suggestive of ADHD. effect found on a vigilance measure, the Audi- tory Continuous Performance Test (ACPT).32 Because Ritalin improves sustained attention RELIABLE DIAGNOSIS OF APD IN or vigilance and decreases behaviors that may THE HYPERACTIVE CHILD otherwise interfere with test taking, children prescribed stimulant medication for ADHD Some clinicians speculate that the high comor- should follow their medication regime as usual bidity of ADHD and APD may be related to when seen for auditory processing testing. the inherent inattention of the child rather than pure auditory processing dysfunction.20,28 One of the misconceptions about children with MANAGEMENT OF ADHD ADHD is that they are constantly hyperactive, fidgety and restless. Children with ADHD who There is considerable research investigating evi- are provided frequent reinforcement, novelty, dence-based treatment approaches for the man- strict control, and highly salient rewards and agement of ADHD; however, much less re- punishments can perform behaviorally much search has been done on APD management 27 like their nonhyperactive peers. The reader is approaches. The criteria for empirically sup- referred to published sources for specific rec- ported psychosocial interventions for childhood ommendations for administration procedures mental disorders have been established by the to ensure that the auditory processing evalua- American Psychological Association.33 Stimu- 29,30 tions control for inattention. lant medication, parent training, the use of behavioral interventions in the classroom, and psychotherapy, with a focus on behavior man- REVIEW OF CENTRAL NERVOUS agement and education, all meet criteria for STIMULANT (CNS) MEDICATION well-established treatments for ADHD.34 Ap- EFFECTS ON APD proximately 70 to 80% of children respond positively to stimulant medication, with an even To date, there have been four conflicting stud- greater number of children responding favor- ies that have investigated the effects of Ritalin ably if several stimulant trials are conducted. Of on the APD test performance of children with the remaining children, the medication either is either ADHD, APD, or both. Three studies not of therapeutic benefit or the adverse side ef- found a medication effect,23,24,31 while a more fects outweigh the advantages. Of those chil- well-controlled study did not find a medica- dren who respond positively to medication, their tion effect.22 The conflict likely stems from the behavioral functioning is improved, but is far fact that the earlier studies (1) did not control from being normalized. Training parents in con- for learning effects or peak medication peri- sistency management programs, the use of daily ods,23,31 (2) involved small sample sizes,23,24 (3) report cards that incorporate novelty and imme- used different criteria for selection of children diate feedback regarding performance, and be- with APD or ADHD,23,24,31 (4) provided de- havioral interventions focusing on social skills scriptive rather than statistical analysis,23 and training and compliance using intensive behav- (5) did not clinically titrate medication.23,24 ioral interventions complement or in some cases The Tillery et al study used a double-blind, provide the basis for effective management of placebo-controlled design while controlling for those with ADHD.34 learning, maturation, and fatigue effects among The results of the Multimodal Treatment a large group of children clinically diagnosed Study of ADHD (MTA Study), sponsored by with ADHD and APD, and who had been re- the National Institute of Mental Health and 342 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Department of Education was conducted at six the day may be avoided, simplifying the phar- different sites throughout the United States macologic management of ADHD. Another and one additional site in Canada.35–37 The medication, Atomoxetine, a noradrenergic agent, study compared four groups of children with will likely obtain Food and Drug Administra- ADHD (N=578). One group received medication approval later this year. tion alone in a very carefully titrated fashion, which is not particularly characteristic of most clinical practices. The second group partici- MANAGEMENT OF APD / ADHD pated in a psychosocial treatment program based largely on behavioral interventions, including Criteria for evidence-based treatment of APD parent training and a behavioral treatment pro- are only beginning to be established. gram based primarily on that described by Pel- APD therapeutic and management strate- ham.34,38,39 Another group received a combina- gies have been detailed in the literature,14,19,30,41–43 tion of both interventions and the last group with a recognized difference between the man- received community care and was to function agement and remediation of APD. Remedia- generally as a control group. tion efforts strive to change auditory function; The details of the MTA study are provided management approaches attempt to alter be- in several publications.35–37 In general, children havioral performance due to the application of who received the two medication treatments compensatory strategies.44 fared better in having their ADHD sympto- Reports of the efficacy of various remedia- matology reduced. Parents were found to pre- tion and management approaches for APD are fer nonpharmacologic interventions; however, limited compared to the evidence-based crite- the combined treatment approaches yielded ria establishing treatments for ADHD. Med- benefits not obtained with either medication ication is effective for ADHD and ineffective or therapy alone. for APD,22 while therapeutic measures for APD The effectiveness of stimulant medication are recommended with the intent to improve therapy in the management of children with auditory function. When the two disorders ADHD is well documented.1 Ritalin and other occur comorbidly, there are no established evi- stimulant medications can help normalize sus- dence-based treatments. Thus, the clinician’s tained attention and reduce some of the associ- only alternative is to creatively combine man- ated features of the disorder in order to im- agement strategies. Table 2 illustrates some of prove successful management. The range of the evidence-based management approaches stimulant medications available, and the sec- for ADHD, as well as some suggested manage- ond line medications, such as Clonidine, Well- ment approaches for APD and combined butrin, and selective serotonin reuptake in- ADHD/APD. Because there is a paucity of ef- hibitors (SSRIs), such as Paxil, provide a range ficacy data regarding effective treatment of of pharmacologic options so that medication children with both disorders, management of management may be individualized depending these children remains speculative. Treatments on the symptoms any particular child is pre- for ADHD may be contraindicated for chil- senting. Because ADHD is a disorder that is dren with APD and vice versa. Therefore, a re- co-morbid with other disorders, poly-pharma- liable diagnosis of both disorders is necessary cologic treatment is often indicated.40 for the beginning of effective management. Medication management remains at the forefront of treatment for children with ADHD. In addition to Ritalin, newer stimulant medica- EFFECTIVE CASE MANAGEMENT: tions shown to have positive therapeutic value ADHD, APD, LD are being released. Adderall, Adderall XR, Con- certa, Metadate, Ritalin LA, and Focalin are all The importance of an accurate differential di- stimulant medications that provide a longer du- agnosis in the management of children with ration effect so that multiple dosing throughout attention related disorders might be best illus- DIAGNOSIS AND MANAGEMENT OF APD AND ADHD/KELLER, TILLERY 343

Table 2 Contrasting Management Strategies for ADHD, ADHD/APD, and APD Strategy ADHD ADHD/APD APD

Medication X X No Novelty X ? ? Immediate feedback X ? ? Highly salient rewards and punishments X ? ? Parent training X ? ? Low level background stimulation (e.g., music) X ? ? Psychotherapy X ? ? Daily report cards X ? ? Social skills training X ? ? Decreased work load X X X Self advocacy X X X Educate parents/families X X X Flexibility in teaching style X X X Pre-tutoring X X X Preferential seating X X X Repetition of directions X X X Environmental modifications X X X Organization skills X X X Auditory processing therapy NA ? X Metacognitive approaches ? ? X Auditory trainer ? ? X Redundancy ? ? X Highly structured teachers ? ? X Counseling ? ? X NA, not applicable; ?, unknown. trated using two case studies of children who AUDIOLOGIC EVALUATION were assessed for behavioral and school adjust- Andrea was found to exhibit normal peripheral ment difficulties. Given the overlapping be- hearing, bilaterally. She failed two of the three haviors that these children present with, diag- APD subtests by five standard deviations, show- nosis has often been contingent upon whether ing evidence of Tolerance-Fading Memory and or not they visit the audiologist or psychologist Decoding types of APD. The three APD tests first.27,45,46 Given the co-morbidity of these were the Staggered Spondaic Word (SSW) disorders, it becomes necessary to comprehen- Test,47 Phonemic Synthesis (PS) Test,48 and a sively evaluate children in order to determine speech-in-noise test.49 She received 17 individ- whether they may be exhibiting one or more of ualized auditory processing therapy sessions that these often overlapping conditions. consisted of targeting phonemic awareness (auditory closure,14,41 rhyming,29,50 synthesis,51 and analysis52). Because she evidenced extreme motor Case One: APD without ADHD activity, she was referred to a psychologist after completing the ninth therapy session. Andrea first presented to the audiologist at 5 years of age because of her inability to accu- PSYCHOLOGIC EVALUATION rately follow directions, and her consistent mis- Andrea was described by her parents as having interpretation of spoken messages. She had a had a “rough five years,” that she was a highly history of otitis media and hyperactivity. persistent child bordering on obsessiveness, and 344 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

was often in a negative mood state. Her atten- perience pronounced delays in reading acquisition on a continuous performance test32 was weak tion. Her reading scores were consistently above for her age, and on a screening test for APD53 the 90th percentile, possibly related to the in- her overall performance fell at the 7th percentile. dividualized auditory processing therapy ses- A neuropsychologic examination yielded over- sions she received. Andrea’s hyperactivity, which all average measured intelligence, but with per- appeared to be ADHD, was instead a behavior formance on immediate memory tasks falling associated with her NLD and APD. at the 2nd percentile, raising the possibility that attention factors might have been suppressing her performance because attention is a prereq- Case Two: ADHD without APD uisite for remembering. She presented with significant motor activity suggestive of ADHD, Cindy first presented for psychologic evalua- but diagnosis was deferred given her young age tion at 6 years of age. She was born 2 months and the auditory processing weaknesses that premature and showed no evidence of any in- she was manifesting. tracranial bleeding on a computerized axial tomography (CAT) scan. Motor milestones had MANAGEMENT been delayed and she was subsequently diag- In Andrea’s case, overall management consisted nosed with cerebral palsy. of addressing her severe auditory processing deficits. Besides the above-mentioned process- PSYCHOLOGIC EVALUATION ing therapies, Andrea also benefited from a co- On evaluation, Cindy obtained a verbal score of operative school district and supportive parents 107 and a performance score of 73 on the employing many of the strategies listed in Table Wechsler Scales. She was diagnosed as having 2. On an intellectual evaluation at 9 years of NLD with average verbal memory abilities, but age, she manifested a significant disparity be- with visual memory skills at the first percentile. tween measured verbal intelligence and visual Neuropsychologic evaluation was consistent perceptual functioning, with a Verbal IQ of 127 with NLD, with compromised performance on and a Performance IQ of 82, and with sup- measures of tactile learning, nonverbal reason- pressed performance on particular subtests, sug- ing skills, and on measures sensitive to the visu- gesting some form of auditory processing dys- ospatial abilities thought to be subserved by the function. Further neuropsychologic evaluation right hemisphere. It was felt that her inatten- confirmed a Nonverbal Learning Disability tion was due to the presence of NLD syndrome (NLD)54 and her earlier attentional weaknesses and possibly APD. had resolved, presumably due to increased right hemisphere maturation (associated with her AUDIOLOGIC EVALUATION NLD). Currently, her phonemic awareness skills Cindy was referred for an auditory processing are above grade level, she continues to be an ex- evaluation due to her poor performance on a cellent reader, and she is not showing classroom screening measure for APD.53 She was found APD behaviors. to exhibit normal peripheral hearing bilater- While she presented with symptomatol- ally, did not present any indication of APD, ogy suggestive of ADHD, and may have been and passed all three APD subtests: SSW, PS, improperly placed on stimulant medication and a speech-in-noise test. However, she dis- had a less thorough assessment been conducted, played a significant number of reversals on the it was the attentional weaknesses associated SSW test. with NLD syndrome, a particular learning disability subtype that is also associated with MANAGEMENT weak attention27,54 and symptoms associated Given the association between reversals and with APD that made her present as a child primary attention disorders, she was subse- with ADHD. Most striking is that children with quently prescribed a low dose of stimulant med- Andrea’s neuropsychologic profile typically ex- ication, to which she responded very well. The DIAGNOSIS AND MANAGEMENT OF APD AND ADHD/KELLER, TILLERY 345 medication enhanced her performance on tasks 2. American Psychiatric Association. Diagnostic and sensitive to attention, as well as her behavioral Statistical Manual of Mental Disorders, 4th ed. functioning both at home and school. In this Washington, DC: Author; 1994 3. Pelham W, Bender M. Peer relationships and hy- instance, audiologic studies were of assistance peractive children: description and treatment. In: in ruling out APD and making the determina- Gadow K, Bailer I, eds. Advances in Learning and tion to consider a trial of stimulant medication Behavioral Disabilities, vol. 1. Greenwich, CT: JAI for what was ADHD associated with NLD Press; 1982 syndrome. 4. Pomeroy J, Sprafkin J, Gadow, K. Minor physical anomalies as a biologic marker for behavioral disorders. J Am Acad Child Adolesc Psychiatr 1988; 27:466–473 CONCLUSIONS 5. Ingersoll B. Your Hyperactive Child. New York: Doubleday; 1988 These two case studies illustrate that reliable 6. Hagerman R, Falkenstein A. An association between recurrent otitis media in infancy and later differential diagnosis is successful when the hyperactivity. Clin Ped 1987;5:253–257 audiologist and psychologist work as a team. 7. Lou H, Henrickson L, Bruhn P. Focal cerebral hy- Reliable differential diagnosis will direct im- poperfusion in children with dysphasia and/or atten- proved evaluation-based treatment approaches tion deficit disorder. Arch Neurol 1984;41:825–829 for children with APD, ADHD, and those with 8. Zametkin A , Nordahl T, Gross M. Cerebral glu- combined APD and ADHD. The use of APD cose metabolism in adults with hyperactivity of sub-types may assist with reliable differential childhood onset. New Eng J Med1990;323:1361– diagnosis and effective management practices 1366 9. Reitan R, Wolfson D. The Halstead-Reitan Neu- of auditory processing, attention, and learning ropsychological Test Battery: Theory and Clinical disorders. Interpretation. Tucson, AZ: Neuropsychology Press; 1985 10. Grant D, Berg E. Wisconsin Card Sort Test. Odessa, FL: Psychological Assessment Resources, Inc.; 1981 ABBREVIATIONS 11. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 2nd ed. ADHD attention deficit hyperactivity dis- Washington DC: Author; 1968 order 12. Milich R, Balentine A, Lynam D. The Predomi- ADHD-C ADHD-combined nantly Inattentive Subtype—not a subtype of ADHD-HI ADHD hyperactivity-impulsive ADHD. ADHD Report 2000;10:1 13. Katz J, Smith P. The Staggered Spondaic Word ADHD-PI ADHD-predominantly inatten- Test: a ten-minute look at the central nervous sys- tion tem through the ears. Ann NY Acad Sci 1991;620: APD auditory processing disorders 233–251 CNS central nervous system 14. Bellis T. Assessment and Management of Central CAT computerized axial tomography Auditory Processing Disorders in the Educational NLD nonverbal learning disability Setting: From Science to Practice. San Diego: CA: PS phonemic synthesis Singular; 1996 15. Katz J. Classification of auditory processing disor- SSRIs selective serotonin reuptake in- ders. In: Katz J, Stecker N, Henderson D, eds. hibitors Central Auditory Processing: A Transdisciplinary SSW staggered spondaic word View. St. Louis, MO: Mosby;1992:81–93 TFM tolerance fading memory 16. Riccio C, Hynd G, Cohen M, Molt L. The Stag- gered Spondaic Word Test: performance of children with attention-deficit hyperactivity disorder. Am J Audiol 1996;5:55–62 REFERENCES 17. Luria A. Aspects of aphasia. J Neuro Sci 1965;2: 278–287 1. Barkley RA. Attention Deficit Hyperactivity Dis- 18. Efron R, Crandall P, Koss P, et al. Central auditory order: A Handbook for Diagnosis and Treatment. processing. III: the ‘cocktail party effect’ and tem- New York: Guilford Press; 1990 poral lobectomy. Brain Lang 1983;19:254–263 346 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

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Tillery K, Katz J, Keller W. Effects of methyl- Psychiatry 1999;56:1073–1086 phenidate (Ritalin™) on auditory performance in 36. Arnold L, Abikoff H, Cantwell D, et al. National children with attention and auditory processing dis- Institute of Mental Heath Collaborative Multi- orders. J Speech Lang Hear Res 2000;43:893–901 modal Treatment Study of children with ADHD 23. Gascon G, Johnson R, Burd L. Central auditory (the MTA). Arch Gen Psychiatry 1997;54:865– processing and attention deficit disorders. J Child 870 Neurol 1986;1:27–33 37. Greenhill L, Abikoff H, Arnold L, et al. Medica- 24. Cook J, Mausbach T, Burd L, et al. A preliminary tion treatment strategies in the MTA Study: rele- study of the relationship between central auditory vance to clinicians and researchers. J Am Acad processing and attention deficit disorder. J Psychia- Child Adolesc Psychiatry 1996;35:1304–1313 try Neurosci 1993;18:130–137 38. Pelham W, Hoza B. Intensive treatment: a summer 25. 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Clinical Efficacy of Electrophysiologic Measures in APD Management Programs

Robert E. Jirsa, Ph.D.1

ABSTRACT

Determining the relative efficacy of various intervention programs for auditory processing disorders (APD) is a major goal in the field of rehabilitative audiology. Currently, because of their widespread availability, the most commonly used measuring tools to assess the central auditory system have been behaviorally based. Such measures do have notable dis- advantages in that they may be influenced by a number of extraneous variables that may impede, or at least influence, efficacy measures. Electrophys- iologic measures offer unique advantages not available from the behavioral measures. A significant amount of research has been completed offering compelling evidence relative to the clinical utility of a number of these electrophysiologic measures, including the maximum length sequences- auditory brainstem response, the middle latency response, the obligatory long latency responses, and the MMN and P3 event-related potentials. This article will review the current research related to electrophyiologic measures and present a rationale for including them in the management program.

KEYWORDS: Electrophysiology, middle latency response, mismatch negativity, P3 event-related potential, speech perception, clinical efficacy

Learning Outcomes: Upon completion of this article, the reader will (1) gain insight into those electrophysiologic protocols most commonly used in the evaluation of APD, (2) become familiar with the research related to the clinical application of these electrophysiologic measures as they relate to APD, and (3) gain insight into the rationale for the use of electrophysiologic measures in assessing the efficacy of clinical intervention with APD.

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Robert E. Jirsa, Ph.D., Department of Communication Disorders, Davis Hall, Rm 012I, Southern Connecticut State University, 501 Crescent Street, New Haven, CT 06515. E-mail: [email protected]. 1Professor of Audiology, Department of Communication Disorders, Southern Connecticut State University, New Haven, Connecticut. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,349,356,ftx,en;sih00219x. 349 350 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

According to the Consensus Conference management program, the monitoring of prog- on Auditory Processing Disorders (APD), a ress throughout the course of therapy is essen- critical need in the management of APDs is de- tial.7 Because they evaluate neurophysiologic termining the efficacy of various intervention responses, and neurophysiologic change often approaches and strategies.1 This may be accom- precedes behavioral change,11,13 electrophysio- plished by comparing pre- and post-therapy per- logic measures may offer a significant advantage formance on selected auditory tests. Behavioral over traditional behavioral measures used to as- tests have the advantage of being widely avail- sess progress in the therapeutic program.3,7,13 able and accessible to clinicians in a variety of settings. Behavioral tests have notable disad- vantages in that they may be influenced by a APPLICABLE number of extraneous variables, such as higher ELECTROPHYSIOLOGIC MEASURES order cognitive and linguistic factors, that may impede, or at least influence, efficacy mea- Investigators in a number of disciplines have sures.2–6 Electrophysiologic measures on the used electrophysiologic measures for years to other hand, are much less influenced by these evaluate aspects of the central nervous system.14 extraneous factors and, in addition, offer many Audiologists have, until rather recently, used unique advantages over behavioral measures.7 electrophysiologic measures primarily in the as- Using electrophysiologic measures, all areas of sessment of the peripheral auditory system. The auditory processing from the auditory nerve8,9 diagnostic usefulness of both the auditory brain- to the auditory cortex can be evaluated with stem response (ABR) and the middle latency minimal influence from extraneous variables response (MLR) has been documented.4,14,15 that often impact behavioral measures.1,5,10 Be- Within the past few years audiologists and hear- cause an auditory processing disorder involves ing scientists have directed their efforts toward the interaction of deficits in the auditory modal- using a variety of electrophysiologic measures to ity at both peripheral and central sites, electro- more fully explore and understand the central physiologic measures are ideally suited for use auditory nervous system.5,12 While there is much in both the diagnosis and management of this yet to be learned, compelling evidence is accu- problem.1,7 Furthermore, in the more general- mulating related to the clinical relevance of a ized area of speech perception, electrophysio- number of electrophysiological measures includ- logic measures may provide the unique oppor- ing the maximum length sequences (MLS),12 tunity to evaluate perception at all levels: (1) the the middle latency response (MLR),15–18 the long acoustic level where acoustic information is en- latency N1 and P2 components,19–22 the mis- coded neurologically, (2) the phonemic level match negativity (MMN), 6,11,13,23–32 and the P3 where basic acoustic contrasts are learned, and event-related-potential (ERP).2,3,33–37 (3) the linguistic or language level.11 Because While each of these electrophysiologic APDs often are associated with deficits in lan- procedures has shown promise of clinical ap- guage development, speech understanding, and plicability, most clinical interest has focused on cognitive function, electrophysiologic measures the MLR, MMN, and the P3. These three are useful in focusing the management program components will be reviewed in more detail. to the dysfunctional areas.3,6,7,12 By facilitating the determination of the primary site of the disorder, auditory problems may be better de- Middle Latency Response fined in relation to other nonauditory problems and appropriate remedial measures initiated.7,11 MLR is an obligatory potential occurring be- In addition, in children with pure auditory pro- tween 10 and 100 msec from stimulus onset. It cessing disorders, electrophysiologic measures is derived from multiple generator sites thought are most useful in determining the extent of in- to reside in auditory specific and nonspecific volvement of the various auditory processes. areas ranging from the upper brainstem and This is a necessary first step in developing the reticular formation, to the thalamus and the appropriate management program.3,12 In any thalamocortical pathways to the posterior tem- EFFICACY OF ELECTROPHYSIOLOGIC MEASURES IN APD MANAGEMENT/JIRSA 351 poral lobe representing the primary auditory of stimulus change within an ongoing acoustic cortex.7 The MLR is highly maturational and stream.6,30 Unlike other long latency ERPs, the in young children is usually identified by a broad MMN appears to be present at birth.32,44 While positive wave, Pa, followed by a negative com- the generator sites are not clearly defined, the ponent, Nb.38,39 By the end of the first decade, MMN is thought to represent primarily the the MLR is usually approaching adult values auditory cortex with some input from the hip- and is identified by a negative trough, Na, fol- pocampus and thalamus.10,13 The waveform is lowed by Pa, then Nb and finally Pb occurring elicited using an oddball paradigm in which a at about 50 msec post onset.38,40 The MLR may string of standard stimuli are infrequently and be generated by either frequency specific tone randomly interrupted by a deviant or oddball pips or the abrupt onset acoustic click. stimulus. According to Naatanen,27 a neural The clinical efficacy of the MLR in exam- trace, or template, is formed by the standard ining children with APDs and other learn- stimulus and held in short-term memory, and ing disorders has been well documented.40–43 the negative shift from baseline (MMN) oc- Musiek has advocated its use in monitoring curs when the central auditory system detects a the maturation of the auditory pathways.7 De- mismatch between this neural trace and the layed maturational patterns are one of the pre- neural template formed by the deviant stimu- sumed etiological factors in various learning lus. It should be noted that the MMN is not an problems including APDs. While the MLR obligatory response, but that it is only gener- may be difficult to correctly interpret in some ated in response to the detection of stimulus young children, its absence in those over 10 change. Because of this, and because of the fact years of age may be indicative of high-level au- that it is passively elicited without the active ditory dysfunction including neurodegenerative participation of the listener, it has accrued sub- problems.7 However, when used in conjunc- stantial clinical interest. tion with behavioral results showing, for exam- Much of the clinical research has focused ple, a significant left ear weakness for speech on the ability of the MMN to detect neurolog- and/or nonspeech material, as well as a nega- ical change during listening training activities. tive neurological diagnosis, the absent, or poorly For example, Kraus and her colleagues13 wanted formed MLR may be an objective marker for to determine whether training listeners to iden- maturational lag.7 In this case, these results tify difficult speech sound contrasts would re- would support a management program focus- sult in neurophysiologic changes within the ing on auditory training activities addressing central auditory system. As expected, through the maturational issues. The MLR would then listening training, subjects learned to behav- be an appropriate means to objectively monitor iorally discriminate the contrasts. In addition, this aspect of the management program. More the listening training also resulted in neuro- specific information regarding maturational physiologic changes evidenced through an en- status may be obtained by recording the MLR hancement in the MMN. Specifically, compar- not just from the vertex, but from each tempo- ing pre-and post-training measures, Kraus et ral lobe as well. Examining for hemispheric al13 noted significant changes in both the dura- and ear asymmetries often provides more de- tion and the magnitude of the MMN and con- finitive information regarding the auditory areas cluded that listening training activities changed affected than using just absolute latency and the neurophysiology of the central auditory amplitude measures.4,43 system and that these changes could be measured and monitored using the MMN. Tremblay et al28 examined the clinical util- Mismatch Negativity ity of the MMN. Their findings were similar to Kraus et al13 and demonstrated that behavioral The mismatch negativity (MMN) is an event- training resulted in neurophysiologic changes related potential (ERP), occurring as a nega- as evidenced by an enhancement in the MMN tive voltage following N1 between 100 and 500 response. Additionally, they found that these msec that reflects the pre-conscious detection neurophysiologic changes were evident in re- 352 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

sponse to untrained stimuli. The authors felt tify, measure, and validate responses.11,29 Fi- that their findings demonstrated the clinical nally, the MMN requires a comparatively long efficacy of the MMN not only in detecting and testing time as well as additional time for off- monitoring neurophysiologic change from lis- line data analysis.22 Until these issues are ad- tening training, but also in establishing whether dressed, routine clinical use of the MMN is or not beneficial changes derived during an au- problematic. ditory training program might generalize to other listening activities. Dalebout and Stack11 further explored the P3 Event-Related Potential clinical implications of the MMN in a well conceived investigation. These authors were in- The P3 auditory event-related potential terested in determining whether or not the (AERP), which occurs roughly from 300 to 700 MMN could be elicited by synthetically gener- msec,2,45 is similar to the MMN in that it is a ated speech contrasts that were not behav- nonobligatory waveform elicited using an odd- iorally differentiated by listeners. Subjects were ball paradigm. It also is referred to as the P3b to asked to take part in a behavioral forced choice separate it from an earlier occurring nonatten- discrimination task involving stimulus pairs tive waveform often labeled as P3a.36 Unlike the along the /da-ga/ continuum that differed only MMN, however, the P3 is not passively elicited, on the basis of the starting frequency of the f2 but requires the active participation of the lis- and f3 formant transitions. For each listener, tener in attending to specific stimuli in an ongo- MMN data were collected using the same ing train of standard stimuli.35,46 Also, unlike stimuli used in the behavioral task. Comparing the MMN, the P3 matures somewhat later than both behavioral and electrophysiologic results the earlier waves with several studies showing a for each of the stimulus contrasts, the authors decrease in latency and an increase in amplitude found the MMN present not only for contrasts from 5 through 16 years of age, followed by a that were differentiated behaviorally, but also progressive decrease in amplitude and an infor those contrasts that could not be differenti- crease in latency throughout adulthood.47–49 ated behaviorally. The authors noted that their While there is considerable controversy regard- findings lend support to the concept that there ing the neural generator sites for the P3, accu- are varying levels of processing for speech per- mulating evidence suggests involvement of the ception. As noted in the introduction, these thalamus, inferior parietal lobe, temporal lobe, levels range from the acoustic level, to the dorsolateral prefrontal cortex, cingulated cortex, phonemic level, and finally to the higher order amygdala, and the hippocampus.36 linguistic level. The MMN appears to reflect Because generation of the P3 does require the pre-conscious acoustic level and provides a active listener participation, it is widely recog- neurophysiologic way of defining levels of au- nized as a physiologic measure of cognitive ditory processing as well as differentiating those processing.2 Thus, the P3 reflects processes re- individuals who have primary difficulty at the lated to attention, decision-making, and mem- acoustic level from those with problems at the ory updating. P3 latency appears to be a func- higher level of processing. tion of stimulus evaluation time including the While the MMN appears to have sub- recognition and categorization of a stimulus,44 stantial clinical potential, further research is re- the speed of information processing,47 and quired before it can become clinically viable.7,11 short-term working memory processes.37 P3 One issue centers around the detectability of amplitude appears to be related to the subjec- the MMN. Because the MMN is not consis- tive probability of the stimulus, stimulus mean- tently identifiable in normal listeners, research ing, and information processing.50 is needed to explore methods of improving Because the P3 is related to the active state MMN detectability.11 This is related to a sec- of the listener, it has been extensively used to ond issue in that there is currently no stan- evaluate various aspects of psychophysiology, dardization for the methodology used to iden- psychopathology, and aging,48,49,51 In general, EFFICACY OF ELECTROPHYSIOLOGIC MEASURES IN APD MANAGEMENT/JIRSA 353 results have shown increases in latency and de- nitive levels of processing,46 together these neu- creases in amplitude in the clinical popula- rophysiologic measures may provide a means for tion.2 In addition, the P3 has been used to in- more precisely identifying the auditory capabili- vestigate various learning and developmental ties of individuals diagnosed with APDs, and as- processes in both children and adults, includ- sist in establishing the most appropriate therapy ing hyperactivity,52 and language and motor program. Certainly, individuals whose auditory speech disorders.40 problems stem from deficits in the neurophysio- The P3 has been investigated in children logic processes underlying speech perception with APDs. Jirsa and Clontz2 compared chil- would require a different management program dren with confirmed APDs to age matched from those whose difficulties reside at the higher controls and observed significant increases in levels of processing. Furthermore, a recent inves- latency and decreases in amplitude in the clini- tigation by Salamat and McPherson,35 using a cal group. In addition, comparing performance sustained attention task at various interstimulus on behavioral measures to the P3 results, the intervals to generate the P3, demonstrated the authors observed a relationship between P3 la- efficacy of using the P3 to quantify attentional tency and amplitude, and deficits in selective processes. The P3 may provide a diagnostic attention, short-term memory, and auditory means of differentiating those with primarily at- discrimination ability. tentional problems from those with auditory- The clinical relevance of the P3 in a man- based problems. agement program was investigated by Jirsa.3 In this study, two groups of children were evaluated behaviorally and electrophysiologically SUMMARY and confirmed to have APDs. One group received 14 weeks of auditory training therapy The electrophysiologic measures discussed in twice a week and the other group served as the this section hold much promise in the diagno- controls and received no therapy. Following the sis and management of APDs when used in 14-week program, all children in both groups conjunction with their behavioral counterparts. were re-evaluated. Children in the clinical group Because a critical component of any manage- showed a significant decrease in P3 latency and ment program is an accurate diagnosis of the a significant increase in P3 amplitude follow- problem, one of the strengths of these mea- ing the treatment program. No changes were sures is the potential to be able to identify and noted in the control group. Children in the clin- describe problems at all levels of auditory pro- ical group also demonstrated significant im- cessing. Both the MMN and the N1-P2 com- provements on the behavioral test battery. plex, as well as perhaps the MLS-ABR, hold Results such as these support the clinical promise of providing critical information at the utility of the P3. Because it does appear to be pre-attentive neurophysiologic level of process- sensitive to behavioral changes resulting from a ing, while the P3 provides information relative therapeutic program, the P3 may be most useful to the higher levels of processing. In addition in monitoring therapy progress. Because the P3 to providing diagnostic data to direct therapy, can be elicited by a variety of stimuli, including electrophysiological measures provide an excel- phonemes and speech contrasts, it would be use- lent means of monitoring therapy progress. By ful in directing the focus of therapy in discrimi- providing information relative to the underly- nation tasks, or for assessing sensitivity to fre- ing neurophysiology in conjunction with be- quency and intensity changes. Also, the P3, havioral change, these measures can serve a when used in conjunction with the MMN, may vital function in focusing the management pro- provide an objective means for evaluating the gram to achieve the best possible outcome. As various levels of speech perception. Because the research continues in this area, there is every MMN has been shown to reflect the pre-atten- reason to believe that the clinical efficacy of tive auditory level of processing,11 and the P3 has electrophysiologic measures will become even been shown to reflect activity at the higher cog- more apparent. 354 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

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Treatment and Evaluation Indices of Auditory Processing Disorders

Hanna Putter-Katz, Ph.D.,1 Limor Adi-Ben Said, M.A.,1 Irit Feldman, M.A.,1 Dana Miran, B.A.,1 Dana Kushnir, M.A.,1 Chava Muchnik, Ph.D.,1 and Minka Hildesheimer, Ph.D.1

ABSTRACT

Listening skills were compared before and after a structured intervention program for a group of 20 children with auditory processing disorders (APD). Comparisons of pre- and post- management measures indicated a significant increase in speech recognition performance in degraded listening conditions (background noise and competing speech). The APD management approach was integrative and included top-down and bottom-up strategies. These findings add to a growing body of literature suggesting that interactive auditory training can improve communication skills.

KEYWORDS: Auditory processing disorder, auditory learning, management, degraded listening conditions

Learning Outcomes: Upon completion of this article, the reader will (1) become familiar with one of the measures of auditory processing, the index of performance accuracy, which reflects a global assessment of auditory information processing; (2) recognize the value of performance accuracy scores in degraded listening conditions in evaluating treatment efficacy for auditory processing disorders; and (3) recognize some of the limitations of the performance accuracy index and the possible contribution of temporal measures in indicating auditory processing difficulties and in evaluating treatment efficacy for auditory processing disorders.

The population manifesting auditory pro- ing as a function of age, peripheral hearing sen- cessing disorders (APD) consists of subgroups sitivity1,2 and neurological status. Furthermore, based on diagnostic findings and diverse func- because APD affects information processing tional deficit profiles. A number of factors con- ranging from sound reception to discourse un- tribute to the variability of functional deficits. derstanding, there is considerable opportunity Subjects with APD are heterogeneous, differ- for various types and degrees of disruption.3 Fi-

Management of Auditory Processing Disorders; Editor in Chief, Catherine V. Palmer, Ph.D.; Guest Editor, Gail D. Chermak, Ph.D. Seminars in Hearing, volume 23, number 4, 2002. Address for correspondence and reprint requests: Minka Hildesheimer, Ph.D., Speech and Hearing Center, Department of Communication Disorders, Sheba Medical Center, Tel-Hashomer, 52621 Israel. E-mail: [email protected]. 1Speech and Hearing Center, Chaim Sheba Medical Center, Tel Hashomer, Israel, and Department of Communication Disorders, Tel Aviv University, Tel Aviv, Israel. Copyright © 2002 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. 00734-0451,p;2002,23,04,357,364,ftx,en;sih00229x. 357 358 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

nally, a range of evaluation procedures are used based partly on variable functional deficits and to diagnose APD, including a variety of audi- on individual listening challenges. Thus, in the tory stimuli (i.e., verbal/non-verbal; synthesized/ present study we evaluated the efficacy of in- natural), differing tasks (i.e., auditory/ phono- tervention in a group of 20 children diagnosed logical/semantic), and several presentation with APD at the Speech and Hearing Center modes (i.e., monotic/dichotic/binaural). Given of the Sheba Medical Center in Tel-Hashomer, the multiplicity of factors underlying the inter- Israel. The present report is restricted to APD subject variability of deficits involved in APD,4 in children whose peripheral hearing and intel- most reports concerning APD management ligence were within normal range and without have been case studies.5–7 Few group studies any known neurological pathology. Treatment of APD treatment have been reported in the efficacy was evaluated by measuring behavioral literature.8–10 speech performance accuracy in the presence Among the demands placed on the audi- of competing noise and competing speech. tory system during everyday listening is the separation of speech from background noise.11 Not surprisingly, most individuals with APD METHOD demonstrate particular communication difficulties in noise.11–15 Increased susceptibility to Participants masking, dichotic listening and selective attention deficits, and temporal processing difficul- Twenty children between 7 years and 11 ties are the most frequently reported deficits in months, and 14 years and 4 months of age children with APD.3 The complex process of (mean age = 9.4; SD = 1.8) participated in the speech recognition requires central pattern rec- APD treatment program. The participants (8 ognition, as well as detailed analysis of sensory girls and 12 boys) were native Hebrew speakers information.16 Children are especially vulnera- and were referred for central auditory assess- ble to degraded listening environments, achiev- ment due to listening difficulties and one of ing lower speech recognition scores than adults the following symptoms: deficient spoken and to spectrally degraded speech.16 Part of the written language comprehension, limited at- speech recognition deficit observed in younger tention, or academic underachievement. Their children with APD is due to their inability to most common behavioral complaints were dif- fully use sensory information; part of the ficulties in understanding verbal stimuli in the deficit is due to their incomplete linguistic and presence of noise or competing speech. All had cognitive development. Despite general ac- hearing sensitivity within normal limits bilat- knowledgment that competing noise and com- erally,17 excellent word recognition abilities in peting speech excessively tax auditory percep- quiet, normal middle ear function, normal au- tion, there are only a few reports on the effects ditory brain stem response (ABR), and normal of management on auditory behaviors in these acoustic reflex thresholds. Their intelligence difficult listening situations among the popula- was within normal range without psychologi- tion with APD. cal or emotional difficulties or known neuro- Management of APD is designed to im- logical complications. prove listening skills and spoken language comprehension.14 The intervention techniques generally are classified into two categories: (1) PROCEDURE enhancement of the primary signal via manip- ulation of the listening environment, and (2) APD Evaluation specific training of auditory skills. The latter frequently includes the teaching of compensa- All participants underwent an auditory process- tory strategies that allow the child to function ing evaluation using conventionally recom- better in the classroom and at home.6 The effi- mended measures to assess the functional in- cacy of these programs is not uniform across tegrity of the auditory system. The auditory children with APD.5 This variability may be assessment was conducted in three sessions at TREATMENT AND EVALUATION INDICES OF APD/PUTTER-KATZ ET AL 359 the Speech and Hearing Clinic of the Sheba ria for treatment included the APD diagnosis Medical Center. In the first session, a routine au- based on this assessment protocol and a co- diologic evaluation consisting of pure-tone air existing report of difficulties in auditory per- and bone conduction, speech reception thresh- formance by the parents, teachers, speech and old, word recognition, immittance testing, acous- hearing clinicians or by the child.12 tic reflex testing, ABR and transient evoked otoacoustic emissions (TEOAE) was conducted. Each child and his or her parents were inter- viewed prior to central auditory testing, and APD Management thorough information regarding presenting complaints, academic abilities, and developmental All participants were scheduled for one 45 min and medical history were obtained in the second treatment session per week,8 extending over a session. four-month period (i.e., 13–15 sessions). Par- Central auditory testing was conducted in ticipants were divided into four groups of 5 the third session, which consisted of the Com- subjects each for technical clinical constraints. peting Sentences (i.e., binaural separation or se- Treatment sessions were conducted by 2 speech lective attention) test,19 a speech-in-noise test,20 and hearing clinicians experienced in auditory gap detection, and masking level differences processing difficulties in children. The APD (MLD). Two versions of the competing sen- treatment sessions were held both in a stan- tences tests were administered. One version con- dard therapy room and in the sound-treated tained three word sentences (i.e., short compet- room of the Speech and Hearing Center. The ing) and the other version contained five word main goal of the APD management was to en- sentences (i.e., long competing). The speech-in- able the children to better cope with the vari- noise test20 is a monaural low-redundancy speech ous auditory demands placed upon them at task that presents monosyllabic words in speech home and at school. The APD management noise. Speech tests were adapted for presentation program focused on environmental modifica- in Hebrew. tions, remediation techniques, and compensa- Gap detection and the MLD procedure tory strategies.12,14 are nonverbal, temporal auditory tasks. Partici- pants were required to detect gaps in white noise bursts presented monaurally and to de- ENVIRONMENTAL MODIFICATION AND tect the presence of a binaurally presented 500 TEACHING SUGGESTIONS Hz tone in binaural white noise. Rest periods The children’s teachers were given a brief ex- of 5 to 15 min were provided as needed be- planation of the nature of APD and the ways it tween test conditions. Participants were diag- might impact school activities. Teachers were nosed with APD on the basis of abnormal per- instructed to try to keep the learning environ- formance (at least one standard deviation (SD) ment highly redundant. Some of the recom- below the mean)4 in either ear on any one test. mendations they were given included decreasing This criterion was based on normative data ac- background noise, using preferential seating, cumulated at our clinic. On the basis of perfor- and using a tape-recorder in lectures. The im- mance on the pre-treatment central speech tests portance of the educator’s involvement and co- two subgroups were observed. Group I in- operation was emphasized.12 cluded 11 subjects who presented reduced performance on the speech in noise test and normal performance on the dichotic tasks. Group REMEDIATION TECHNIQUES II included 9 subjects who demonstrated poor The main goal of this component was to im- performance on both speech in noise and di- prove overall auditory processing abilities, es- chotic listening tasks. Of the children who were pecially in a noisy environment.21,22 Tasks in- able to complete the nonverbal tests, most dem- cluded: listening and comprehension activities onstrated abnormal MLDs, while gap detec- in the presence of noise and competing verbal tion was within normal range. Inclusion crite- stimuli, and selective and divided attention tasks. 360 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Treatment tasks were built hierarchically as a The effects of the APD management on function of language complexity, and different speech perception performance were analyzed levels of background noise and competing separately for Group I and Group II and com- speech. Each treatment session was specifically pared between subgroups. Each subject served designed to build progressively upon prior ac- as his or her own control; auditory performance complishments in an effort to maximize prog- was compared pre- and post- treatment within ress.8 each subject. Figure 1 displays the pre-treatment performance accuracy (in percent correct) of the COMPENSATORY STRATEGIES pre-treatment speech test battery for both The goal of this component of the manage- groups. A multivariate analysis of variance ment program was to assist the child in learn- (MANOVA) with repeated measures revealed ing to cope with auditory problems by using the no difference between groups in speech in following strategies: auditory closure, speech- noise scores (F=1.02, df=1,18, p> 0.05 for the reading, assistive listening (i.e., demonstration right ear; F=0.22, df=1,18, p> 0.05 for the left and trial of frequency modulated [FM] de- ear). Significant differences between groups vices), and metacognitive awareness enhance- were found for both ears in the performance on ment. Parental involvement was especially inte- the short version of competing sentences gral to this component of the management (F=13.86, df= 1,18, p< 0.005 for the right ear; program. Parents were pivotal to ensuring the F=5.62, df= 1, 18, p< 0.05 for the left ear) and children applied these compensatory strategies for the right ear results of the long version of beyond the intervention sessions. Moreover, this test (F=17.73, df=1,18, p< 0.0005). These parents were essential to the subjective assess- results confirmed the groups’ differentiation ment of treatment efficacy. and classification. Pre- and post-treatment central speech test results for Group I are shown in Table 1. A significant improvement was found following treat- RESULTS ment for the right ear in the speech in noise test (p< 0.05). No differences were found for All test subjects completed the treatment pro- the performance accuracy scores of the left ear gram. At the end of the intervention program, pre- and post-treatment. No differences were all subjects were re-administered the central observed for the pre- and post-treatment per- speech test battery (i.e., speech in noise and formance accuracy scores of Group I in the di- competing sentences). chotic listening tasks.

Figure 1 Mean and standard errors of pre-treatment performance accuracy scores (in percent correct) of the speech test battery for Group I and Group II. rsn, speech-in-noise of the right ear; lsn, speech-in-noise of the left ear; res, lcs, right and left competing sentences; short/long, short and long version of cs. TREATMENT AND EVALUATION INDICES OF APD/PUTTER-KATZ ET AL 361

Table 1 Group I Mean and Standard Deviations of Performance Accuracy (in Percent Correct) Pre- and Post-Treatment Pre-Treatment Post-Treatment Right Left Right Left Test X SD X SD X SD X SD

Speech-in-noise 64.63 6.98 62.63 13.45 74.09* 10.42 72.54 8.3 Short competing sentences 98.09 3.08 88.09 10.6 98.7 1.7 88.4 11.43 Long competing sentences 84.4 19.72 69.2 26.85 88.0 10.88 79.0 17.2 *p<0.05 SD, standard deviation; X, mean.

Table 2 shows pre- and post-treatment ences between groups were found for the right central speech test results for Group II. Signif- ear in the long version of competing sentences icant differences were found for each test in (F=8.54, df=1, 18, p< 0.05) and for speech in the battery following intervention, except the noise of the left ear (F=5.34, df=1, 18, p< 0.05) short competing sentences test for the right ear (p< 0.05)(Table 3). Figure 2 displays the posttreatment per- DISCUSSION formance accuracy (in percent correct) of the speech test battery of both groups. MANOVA The APD management described and evalu- with repeated measures indicated no differ- ated in the present study was based on an inte- ences between groups for speech in noise of the grative approach predicted on the growing body right ear (F= 3.78, df=1,18, p> 0.05), the short of literature suggesting that central auditory pro- version of competing sentences (F=3.43, df=1, cessing invokes both bottom-up and top-down 18, p> 0.05, for the right ear; F= 1.28, df=1,18, processes3. In normally hearing individuals, au- p> 0.05 for the left ear), or for the left ear for ditory processing is regulated by passive and ac- the long version of competing sentences (F= tive learning, resulting in experience-dependent 1.24, df= 1, 18, p> 0.05). Significant differ- enhancements of performance.2 The impor-

Table 2 Group II Mean and Standard Deviations of Performance Accuracy (in Percent Correct) Pre- and Post-Treatment Pre-Treatment Post-Treatment Right Left Right Left Tests X SD X SD X SD X SD

Speech-in-noise 67.33 5.91 65.66 15.7 81.77* 6.2 81.33* 8.66 Short dichotic sentences 66.2 26.78 59.55 34.88 82.33 27.99 79.66* 21.23 Long dichotic sentences 31.33 34.07 48.44 29.47 62.11* 24.55 65.88* 29.26 *p<0.05 SD, standard deviation; X, mean.

Table 3 T-tests for Pre- and Post-Treatment Measures of Auditory Processing for Group Auditory Task Right Left

Speech-in-noise t =6.7 df=8 p =.0002 t =2.47 df=8 p =.04 Short competing sentences t =1.73 df=8 p > .05 t =3.32 df=8 p =.01 Long competing sentences t =3.45 df=8 p =.0087 t =2.39 df=8 p =.043 362 SEMINARS IN HEARING/VOLUME 23, NUMBER 4 2002

Figure 2 Mean and standard error of post-treatment performance accuracy scores (in percent correct) of the speech test battery for Group I and Group II. rsn, speech-in-noise of the right ear; lsn, speech-in-noise of the left ear; res, lcs, right and left competing sentences; short/long, short and long version of cs.

tance of integrative processing of auditory in- ments in overall listening behaviors and abilities formation (i.e., sensory/peripheral and central) at home and in the classroom. These results is underscored in children16 who are developing suggest that skills generalized from the clinic to cognitive and linguistic abilities. Moreover, for other speech communication situations.24 children with APD, internal distortions degrade Although the children were classified into the auditory signal so that top-down process- two groups based on different patterns of per- ing typically predominates in most listening formance on the central auditory speech tests situations, particularly those in which complex prior to intervention, little difference was ob- linguistic and cognitive demands are coupled served between groups following treatment. with background noise. Therefore, management (Following treatment the two groups differed of APD should be based upon an integrative only in left ear speech in noise performance and top-down and bottom-up approach that con- right ear performance on the long competing siders both skill-specific deficits and cognitive- sentence test.) While Group II demonstrated linguistic features.23 improvement following treatment on almost The focus of the APD integrative man- all measures, Group I demonstrated improved agement in the present study was on auditory speech in noise for the right ear only. The dif- learning.2 Specifically, the children acquired ference in response to treatment may reflect the auditory experience in hierarchically structured difference in severity of the APD between listening conditions that are known to be chal- groups. In addition, the limited improvement lenging for individuals with APD. This ap- of Group I following treatment may be more a proach is consistent with the ultimate goal of reflection of the limitations of the outcome APD management in children to maximize the measures than a true absence of behavioral auditory learning abilities so that communica- change. Behavioral tests that reveal functional tion and classroom learning experiences are processing deficits reflect only the end product more successful.14,23 and not the whole process. Subjects with APD The auditory function of the children par- usually achieve high word recognition scores to ticipating in the present study demonstrated undistorted speech materials. However, as re- some improvement following intervention, as ported in the literature and on the basis of our indicated by improved performance on speech experience, their auditory behavior differs from in noise and competing sentences tasks. These that of control subjects even when their perfor- tests give a direct assessment of auditory percep- mance accuracy scores are high. Recent data tual and functional deficits.3 In addition, these from our center indicate the potential of time- improvements were corroborated by children, based measures to complement information ob- parents and teachers who reported improve- tained from speech recognition testing of sub- TREATMENT AND EVALUATION INDICES OF APD/PUTTER-KATZ ET AL 363 jects with APD. Preliminary results indicate 2. Moore D, Hogan SC, Kacelnik O, et al. Auditory longer reaction time (RT) in subjects with APD learning as a cause and treatment of central dys- compared to controls, despite similar high speech function. Audiol Neurootol 2001;6:216–220 3. Chermak GD. Central testing. In: Gerber SE, ed. recognition scores. These results, although pre- The Handbook of Pediatric Audiology. Washing- liminary, imply that RT may be a useful crite- ton, DC: Gallaudet University Press; 1996:206–253 rion to evaluate speech recognition in degraded 4. Ferre J, Willber L. Normal and learning disabled listening conditions and to evaluate manage- children’s central auditory processing skills: an ex- ment efficacy. perimental test battery. Ear Hear 1986;7:336–343 Studying children who undergo APD 5. Musiek FE. Habilitation and management of audi- management holds the promise of providing tory processing disorders: overview of selected pro- important insights into perceptual changes as- cedures. J Am Acad Audiol 1999;10:329–342 6. Bellis TJ, Ferre JM. Multidimensional Approach to sociated with auditory learning. It is important the differential diagnosis of central auditory pro- to determine which children might benefit from cessing disorders in children. J Am Acad Audiol intervention and how treatment may alter their 1999;10:319–328 speech processing in everyday listening. The 7. Garstecki D, Hutton CL, Nerbonne MA, Newman auditory processing remediation approach should CW, Smoski WJ. Case study examples using self- incorporate analysis, synthesis, integration and assessment. Ear Hear 1990;11(Suppl):48S–56S interpretation of auditory input for communi- 8. Jirsa RE. The clinical utility of the P3 AERP in chil- cation, and learning as Chermak had already dren with auditory processing disorders. J Speech Hear Res 1992;35:903–912 25 suggested in 1981. Using electrophysiologic 9. Yencer KA. The effects of auditory integration measures (e.g., event-related potentials: MMN, training for children with central auditory process- P300, N400) may complement the behavioral ing disorders. Am J Audiol 1998;7:32–44 test battery used in this study, and provide 10. Hesse G, Netling M, Mohrmann B, Laubert A, more specific information on the various levels Ptok M. 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