Treatments for Decreased Sound Tolerance ( and Misophonia)

Pawel J. Jastreboff, Ph.D., Sc.D.1 and Margaret M. Jastreboff, Ph.D.2

ABSTRACT

Decreased sound tolerance (DST) is an underappreciated condition that affects the lives of a significant portion of the general population. There is lack of agreement regarding definitions, specific components, prevalence, methods of evaluation, and methods of treatment. Limited data are available on the results of treatments. Research is scant and constrained by the lack of an animal model. This article proposes a definition of DST and its division into hyperacusis and misophonia. The potential mechanisms of these phenomena are out- lined, and the results of treatment performed at Emory University are presented. Out of 201 patients with DST, 165 (82%) showed significant improvement. Of 56 patients with hyperacusis (with or without misophonia), 45 (80%) showed significant improvement. This propor- tion was higher for the group with hyperacusis and concurrent misophonia (33 of 39, or 85%) and lower for patients with hyperacusis only (13 of 17, or 76%). Effectiveness of treatment for misophonia with or without hyperacusis was identical (152 of 184, 83% and 139 of 167, 83%, respectively, for misophonia accompanied by hyperacusis and for misophonia only). Even with current limited knowledge of DST, it is possible to propose specific mechanisms of hyperacusis and misophonia and, based on these mechanisms, to offer treatments in accordance with the neurophysiological model of tinnitus. These treatments are part of Tinnitus Retraining (TRT), which is aimed at concurrently treating tinnitus and DST and alleviating the effects of hearing loss. High effectiveness of the proposed treatments support the postulated mechanisms.

KEYWORDS: Decreased sound tolerance, hyperacusis, misophonia, definitions, treatment

1Department of Otolaryngology, Emory University School Tinnitus, Hyperacusis, and Misophonia; Guest Editors, of , Atlanta, Georgia; 2JHDF, Inc., Columbia, Diane F. Duddy, Au.D. and Laura A. Flowers, Au.D. Maryland. Semin Hear 2014;35:105–120. Copyright # 2014 by Address for correspondence: Pawel J. Jastreboff, Ph.D., Thieme Medical Publishers, Inc., 333 Seventh Avenue, Sc.D., Department of Otolaryngology, Emory University New York, NY 10001, USA. Tel: +1(212) 584-4662. School of Medicine, 550 Peachtree St. NE, Medical Office DOI: http://dx.doi.org/10.1055/s-0034-1372527. Tower 11th Floor, Suite 1130, Atlanta, GA 30308 ISSN 0734-0451. (e-mail: [email protected]). 105 106 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

Learning Outcomes: As a result of this activity, the participant will be able to (1) classify subsets of decreased sound tolerance; (2) list potential mechanisms for hyperacusis and misophonia.

Most people have preferences regarding misophonic patients is quite distinct and there- specific sounds or the level of sound, but these fore they require careful diagnosis. preferences do not affect their everyday lives and interaction with others. Nevertheless, a significant number of people have negative DEFINITIONS reactions such as irritation, tension, , Over the years, various terms have been used to or fear of ordinary sounds that, in turn, nega- describe oversensitivity to ordinary sounds that tively affect their lives. Individuals with de- induce negative reactions. These terms include creased sound tolerance (DST) are unable to hyperacusis, recruitment, hyperacousia, auditory tolerate everyday sounds that do not bother hyperesthesia, dysacousis, auditory dysesthesia, ody- other people. Interestingly, the sounds that nacusis, auditory allodynia, phonophobia, in- evoke negative responses in these individuals creased noise sensitivity, collapsed tolerance level, (see Table 1) are not necessarily loud (e.g., and decreased sound tolerance, with the term power tools or low-flying planes) or moderate hyperacusis used most frequently.1–3 These (e.g., electric shaver or average office sounds). terms have not been precisely defined. Based Indeed, some individuals may be affected by on the literature and our accumulated knowl- soft sounds, such as breathing or chewing. For edge from clinical practice, we proposed to many years, DST was underestimated and define DST as present when a subject exhibits therefore not fully investigated. Perhaps this negative reactions following exposure to sound was because affected individuals sought help that would not evoke the same response in an from clinicians with a variety of specialties average listener.2,4,5 We also postulated that including otology, , , psy- DST consists of two components: hyperacusis chology, , and occupational therapy. and misophonia, which frequently coexist. As a result, DST had no research home or Hyperacusis, the first component of DST, treatment. is present when negative reactions to a sound DST can be present with different levels of depend only on its physical characteristics (i.e., severity and may not necessarily require inter- its spectrum and intensity). The sound’s mean- vention and treatment. This text focuses on ing and the context in which it occurs are clinically significant DST (i.e., DST that both- irrelevant. In turn, this implies that the mech- ers the individual to the extent that he or she anisms responsible for the emergence of hyper- wants to alleviate it). acusis are within the subconscious part of the Individuals affected by DST can be divided auditory pathways.2,4,5 For example, a patient into two distinct groups: (1) Patients who will react identically to the sound of a knife respond consistently to sounds above a certain hitting china in any situation or setting. This intensity; their reactions can be correlated with individual also will react negatively to all other the physical parameters of the sound. These high-intensity sounds. patients are diagnosed with hyperacusis. (2) The second component of DST, misopho- Patients who react to specific patterns of sound nia, is present when an abnormally strong and/or react to sound that occurs in specific reaction occurs to a sound with a specific pattern situations or settings whereas tolerating other and/or meaning to an individual.4,5 The reac- sounds that are frequently much louder. These tion may depend on the environment where the patients are diagnosed with misophonia.Al- offensive sound is presented. The physical though the same sounds may be reported to characteristics of the sound are secondary. In- induce identical reactions in both groups of deed, the strength of the misophonic patient’s patients, the treatment of hyperacusic and reaction is only partially determined by the DECREASED SOUND TOLERANCE/JASTREBOFF AND JASTREBOFF 107

Table 1 Sounds that Evoke Negative à Office sounds (typing on a keyboard, printers, copy Reactions as Reported by Patients machine, fax) Loud rings (phone, doorbell) Other people’s headphones School bell One’s own voice Announcements in a metro, train station, airport, or Specific type of laughter supermarket Children’s voices Announcement on airplane or train Screaming, crying babies Train on a track, particularly under bridge High-pitched voices Low-flying airplanes Sniffing Street sounds Other person breathing in bed, snoring Sound of car brakes or bicycle brakes Other people breathing Sounds of driving on street or highway Lip smacking Dogs barking Sounds of eating Warning sounds (e.g., sirens, car horns, beepers) Swallowing Slamming doors Chewing Sudden sounds (e.g., object dropped on a hard Crunching sound surface) Clipping and filing fingernails Sounds of surgical instruments in an operating room Toothbrush Sounds of a dental procedure Electric shaver Drilling Hair dryer Power tools Flushing toilet Mechanical/motor sounds Keys rattling Leaf blower, lawnmowers Moving hand on a surface Swimming pool pump Chalk on a blackboard Shoveling cement Sound of drawing with a felt-tipped pen Movie theaters, concerts Cat walking on a hardwood floor Social gatherings, parties ÃFrom various texts.3,5,21 Note that sounds such as bird Restaurants, pubs, bars, nightclubs song, running water, wind, and rain are rarely reported as negative.21 School breaks, cafeterias Sporting events Church services TV, radio with volume set by family member with sound’s physical characteristics. Frequently, a normal hearing person with misophonia will respond strongly Other people singing to a soft sound of a specific pattern (e.g., a voice, A musical instrument the sounds of eating), but not react to other, Vacuum cleaner much louder sounds (e.g., loud music). Fur- Boiling water thermore, the individual may react to a given Sound of a refrigerator sound in one setting (such as in his or her home) Utensils hitting china but not react to the same sound in another Cutlery and plates setting (such as in the home of a friend). The Loading dishes in dishwasher patient’s negative reaction to the sound depends Garbage disposal on nonauditory factors such as his or her Popping popcorn previous evaluation of the sound, on the belief Supermarket freezer that the sound is a potential threat, or that Grocery stores exposure to it will be harmful. The sound may Shopping malls be associated with a previous negative experi- 2–5 Crinkly bags ence. The patient’s psychological profile and Crumpling or wrinkling paper the context in which the sound occurs are 2,4,5 Hum of electricity important as well. Hum of a computer A specific category of misophonia called phonophobia occurs when the patient’s fear of 108 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

sound is the dominant emotion.2,4,5 Phono- PREVALENCE OF DST phobia is recognized in clinical psychology, Information on the prevalence of DST is vague. where it is treated the same way as other types There is a lack of agreement on terminology and of sensory phobias, and in neurology, where it is definitions, and even on how such an evaluation one of the symptoms associated with migraines should be performed. No validated question- and treated as part of a chronic neurological naire exists to detect the presence of DST. Some disorder characterized by recurrent headaches. reports indicate high prevalence; for example, The concept of misophonia was created in data obtained from 10,349 randomly selected 2001, after 10 years of clinical work with subjects showed that 15.3% reported DST.10 patients with tinnitus and what we believed Other authors reported lower prevalence.11–13 at the time was hyperacusis, when we recog- There is general agreement that with regard to nized the presence of the two subgroups of hyperacusis, pure tone loudness discomfort levels patients with DST. Patients who reacted neg- (LDLs) must have decreased values. That being atively to specific patterns of sound did not said, there is no consensus on how LDLs should be improve as well as hyperacusic patients to evaluated and, indeed, a variety of methods have classical sound desensitization treatment. In been proposed.14–18 Furthermore, LDLs are not introducing a new categorization of patients typically part of a routine audiological evaluation. with DST, including a new concept and a Importantly, low LDLs by themselves do not specific term to describe patients who reacted prove the presence of hyperacusis as low values in a negative manner to specific patterns of may be due to misophonia. A careful inspection of sound, we combined the word miso (meaning publications reveals that, in some cases, misopho- hate in Greek) to represent patients’ strong nia rather than hyperacusis was present, such as in negative attitudes with the term phonia (mean- reports on Williams syndrome.19,20 ing voice, sound)toformthetermmisopho- On the basis of the tinnitus literature, for nia.4,6 Obviously, it is incorrect to translate which more detailed data are available, it is misophonia literally as hatred or dislike of possible to estimate the prevalence of DST in sound, just as it would be incorrect to translate the general population. Results from the Emory photography to mean light drawing. Unfortu- Tinnitus and Hyperacusis Center indicate 60% nately, such an incorrect interpretation has of patients with tinnitus examined have signifi- been made in the literature. There are patients cant DST.4 Results from other clinicians and who exhibit a general dislike of sound, typically researchers show that 25 to 30% of patients with combined with phonophobia, but they are rare. tinnitus have hyperacusis that requires treat- Although the term misophonia was intro- ment.3,4,21–24 In addition, it has been reported duced in the literature in 20024 and described that 86% of patients with hyperacusis suffer from in the following years,2,3,7,8 in January 2013, tinnitus.25 By accepting an average prevalence of Schro¨der et al redefined misophonia based on clinically significant tinnitus reported in the liter- their work in a psychiatric center and proposed ature as 4%,26 it is possible to calculate that to classify the condition as a new psychiatric clinically significant hyperacusis is present in disorder.9 In our opinion, Schro¨der studied a 1.75% of the general population. As our data population of psychiatric patients who hap- indicate, hyperacusis is present in about half of pened to have misophonia as well. In our patients with DST, and the prevalence of DST in clinical work, we have seen several hundred the general population can be estimated to be misophonic patients (compared with 42 cases 3.5%. Because our data indicate 92% of patients reported by Schro¨der), all evaluated by physi- withDSThavemisophonia,theprevalenceof cians, and in only a few cases did patients misophonia in the general population can be exhibit psychiatric problems. Moreover, our estimated at 3.2%. misophonic patients showed significant im- provement when treated with a combination of counseling and a specific version of sound PRESUMED MECHANISMS therapy (described later) without any need for The mechanisms associated with the emergence psychiatric intervention. of DST, and how negative reactions to sound DECREASED SOUND TOLERANCE/JASTREBOFF AND JASTREBOFF 109 develop, are hypothetical and none of the Table 2 Negative Reactions Frequently proposed mechanisms have been proven. The Reported by Patients with DST lack of an established animal model of hyper- Irritation acusis makes it difficult to assess the validity of Annoyance the proposed mechanisms. Both peripheral and Anger 3,27,28 central mechanisms have been postulated. Tension The impact of stress on the peripheral and Frustration central auditory system involving dynorphins Urge to escape (run) 29 has been proposed, as has the involvement of Urge to cry 30,31 serotonin. Dynorphins are a class of opioid Feeling of physical pain peptides that have been shown to be involved in Feeling of being restrained in doing things modulating pain response, addiction to cocaine, Feeling uncomfortable (discomfort) stress and depression, appetite and circadian Inability to concentrate rhythms, and temperature regulation. Minimal Inability to enjoy things, particularly involving louder experimental and clinical support exists to sup- or specific sounds port either proposition. Increased awareness of sounds (forced to monitor Another proposed mechanism involves sounds) dysfunction of the efferent olivocochlear sys- Fear of sounds 32,33 tems, which have an inhibitory action on Emotional distress the outer hair cell (OHC) and inner hair cell Uneasiness (IHC) systems. The available data argue against Worry this hypothesis in the following ways. Record- Stress ings of otoacoustic emissions in hyperacusis patients have not revealed enhanced emissions, DST, decreased sound tolerance. thereby arguing against overamplification pro- vided by the cochlear amplifier. Importantly, the possibility of involvement of the efferent meaning, and the situation in which it occurs olivocochlear bundles can be excluded due to play a predominant role. Therefore, the reac- the observation that severance of the vestibular tions depend on the misophonic’s past history nerve in humans, within which all efferent and on the association of the sound with olivocochlear fibers are contained, has no im- something negative. Taken together, these facts pact on DST34 nor on auditory performance.35 suggest that although the negative reactions to In analyzing the potential mechanisms of sound are identical, the mechanisms yielding hyperacusis and misophonia, it is essential to these reactions are different for hyperacusis and consider the following. First, the negative re- misophonia. actions induced by hyperacusis and misophonia In cases of clinically significant DST, a are identical and it is impossible to distinguish sound evokes the overactivation of the limbic between the two conditions on that basis. We and autonomic nervous systems. Taking into can imply, however, that common brain systems account the factors listed previously, it is possi- are responsible for the negative reactions ble to consider two different scenarios leading evoked by hyperacusis and misophonia and to such a state. In one scenario, when the sound that these reactions (see Table 2) argue for reaches the cochlea it is overamplified exclu- the dominant role played by the limbic and sively within the auditory system, (1) during the autonomic nervous systems. Other systems in transduction process performed by the IHCs the brain are involved, but are secondary. and OHCs or (2) at a higher level of the Second, the differentiating factor between subconscious part of the auditory path- the two conditions is that for hyperacusis the ways.2,3,36 In the second scenario, the auditory physical characterization of the offending system works normally, but functional connec- sound is sufficient to assess the other sounds tions between the auditory system and the that would create a problem, whereas for mi- limbic and autonomic nervous systems are sophonia the specific pattern of sound, its enhanced. 110 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

At the peripheral level of the auditory In misophonia, patients react to specific pathways, it is possible to envision enhanced patterns of sound (soft or loud sounds), but do activity of the OHCs that would result in the not have problems with other, even louder overstimulation of IHCs or the enhanced re- sounds. This observation demonstrates that lease of neurotransmitters from the IHCs.2,3,36 the mechanism for misophonia is not within Available data, however, argue against a domi- the auditory pathways, but in functional con- nant peripheral mechanism for DST. For ex- nections of the auditory pathways with other ample, clinical observations show the nearly systems in the brain. The neurophysiological universal dominance of bilateral, symmetrical model of tinnitus can be used to explain the hyperacusis,24 which suggests the central mech- mechanisms of misophonia as well as to delin- anism as dominant. In other words, as in the eate the differences between the mechanisms of case of cochlear dysfunction, there should be hyperacusis and misophonia. cases of clear unilateral hyperacusis. Further- more, if overamplification of the OHCs was present, then a high level of distortion product THE NEUROPHYSIOLOGICAL otoacoustic emissions should be observed, MODEL OF TINNITUS AS A BASIS which is not the case. FOR PROPOSED MECHANISMS OF Research and available clinical data men- HYPERACUSIS AND MISOPHONIA tioned later support the involvement of the AND THEIR TREATMENT central part of the auditory pathways in DST. The fundamental principle of the neurophysio- As is the case for all other sensory systems, the logical model of tinnitus is that in cases of auditory system works according to the dynam- clinically significant tinnitus or DST, several ic balance principle, where the gain on the brain systems are dominant other than the system is modified depending on the input auditory system. Furthermore, the activation level. Thus, when the sound level is low, the of these other systems is responsible for the sensitivity and gain of the auditory system negative emotional and autonomic reactions increases. Animal research has shown that evoked by these conditions. Analysis of these damage to the cochlea or a decrease in auditory reactions points to the essential involvement of input yields a corresponding decrease of the the limbic and autonomic nervous systems. response threshold in a significant proportion In cases of hyperacusis, it is proposed that of neurons in the ventral cochlear nucleus and the problem results from abnormally high am- inferior colliculus.37 These findings have been plification occurring within the auditory path- corroborated by a study of evoked potentials, ways, which, in turn, results in the stimulation which indicated an abnormal increase of gain in of the limbic and autonomic nervous systems the auditory pathways after such manipula- (Fig. 1A). Consequently, the neuronal activity tions.38 The hypothesis of increased gain with- evoked by exposure to (for example) a 70-dB in the central part of the auditory pathways has hearing level (HL) sound in a patient with been discussed and promoted in recent ap- hyperacusis is similar to activity evoked in an proaches to the mechanisms of tinnitus and individual without hyperacusis, following ex- hyperacusis.39 posure to a 120-dB HL sound. In the same way In the previously mentioned scenario, the that such a level of activity would evoke an auditory system alone would be involved with aversive negative reaction in a normal subject, no corresponding evaluation of the sound’s negative reactions would be evoked in a hyper- meaning and without regard to memory, previ- acusis patient who is stimulated by a 70-dB HL ous exposure (which would involve other brain sound. Note, for hyperacusis, the functional systems), or emotional status. The patient’s properties of the connections between the au- reactions would be determined solely by the ditory system and the limbic and autonomic physical characterization of the sound (i.e., its nervous systems are normal and the strong spectrum and intensity). When this behavior is reaction of these systems reflects a high level observed in patients with DST, we diagnose of input to the limbic and autonomic nervous them as having hyperacusis. systems coming from the auditory system. DECREASED SOUND TOLERANCE/JASTREBOFF AND JASTREBOFF 111

Figure 1 Block diagram of potential mechanisms responsible for decreased sound tolerance (DST). (A) Block diagram of potential mechanisms responsible for hyperacusis. Hyperacusis results from abnormal amplifica- tion of sound-evoked activity occurring within the auditory pathways (marked by black lines). (B) Block diagram of potential mechanisms responsible for misophonia. Misophonia results from enhanced functional connections between the auditory and the limbic and autonomic nervous systems for a specific pattern of sound-evoked activity (marked by black lines). Note overamplification of the limbic and autonomic system occurring in both conditions and marked by cross pattern. (Modified from Jastreboff and Jastreboff3).

The situation is dramatically different in treatment of misophonia results in its cases of misophonia (Fig. 1B). In these cases, elimination.4,5 the auditory system works normally. However, The concept of a complex conditioned the functional connections between the audito- stimulus43 plays an important role in misopho- ry and the limbic and autonomic nervous sys- nia. Behavioral neuroscience has documented tems are enhanced for specific patterns of that reaction to a stimulus occurs as a whole, sound.2–5 These connections involve the con- and not to its individual components. A classic scious, cognitive part and the subconscious example has been described in the case of a path, with the subconscious path governed by tinnitus patient.36 The patient perceived tinni- the principle of conditioned reflexes. Our re- tus as a hissing sound that was highly intrusive sults indicate that the subconscious connections during the day and markedly affected his con- play a dominant role in overactivating the centration and life. Paradoxically, although the limbic and autonomic nervous systems.40 As a patient had difficulty sleeping at night prior to result, even if a subject fully understands a given developing tinnitus, his sleep improved after he sound is not dangerous or threatening, strong had tinnitus. A detailed interview revealed he negative reactions are still evoked. had a happy, carefree childhood and that the The proposed mechanisms of misophonia sound of his tinnitus was similar to the loud were recently supported by the results of physi- hissing sound produced by a water cistern in his ological investigations by Edelstein et al.41 The attic bedroom that he heard as he drifted off to authors found experimental evidence that mi- sleep. At bedtime, the similarity of the patient’s sophonia produces distinct autonomic effects, tinnitus to the water cistern, in combination and suggested that the mechanisms of miso- with the darkness and other factors he associat- phonia concern aberrant functional connections ed with going to sleep, created a complex between the auditory and limbic systems. Fur- stimulus that the patient perceived as positive thermore, the overactivation of the autonomic and relaxing. On the other hand, the patient’s nervous system may, in turn, activate the tensor tinnitus was highly intrusive during the day. tympani muscle,5,7 resulting in tensor tympani Thus, the patient’s tinnitus evoked opposite syndrome (e.g., fullness, pulsation, pain in the reactions depending on the copresence of other ear).42 The presence of tensor tympani syn- stimuli, which created the complex stimulus. drome can be documented by measuring im- Similarly, for misophonia the environment mittance over a 30- to 60-second period. may play a significant role and the patient may Tensor tympani syndrome is frequently ob- react to the same sound differently depending served in patients with severe misophonia and on the context and setting in which the sound is 112 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

heard. The purposeful creation of a complex naires need to be further evaluated. Notably, conditioned stimulus, with the offensive sound neither questionnaire differentiates between as its component, is used in one of the protocols hyperacusis and misophonia. There is no pub- to treat misophonia, as discussed later. lished, validated questionnaire for misophonia. For hyperacusis and misophonia, the ex- The approach we are using to evaluate tent of a patient’s reaction to sound will depend DST and its components, as well as to the on his or her emotional status and the coexis- administration and evaluation of LDLs, is tence of factors that induce a negative emotion- based on published forms for structured initial al state (e.g., pain, a vestibular problem, etc.). and follow-up interviews.46 Detailed instruc- These factors directly affect the limbic and tions on how to apply these interviews have autonomic nervous systems, the centers respon- been published.47 The expanded interview is sible for inducing a negative reaction, and crucial to assess DST. During this interview, increase their sensitivity and reactivity stress is placed on identifying sounds that evoke (Fig. 1A and 1B). negative reactions in the patient as well as sounds that are well tolerated. It is important to check for the presence of any discrepancies EVALUATION OF HYPERACUSIS between the patient’s reactions and the intensity AND MISOPHONIA of the sound. The existence of these discrep- There is lack of agreement as well as significant ancies indicates the presence of misophonia. confusion regarding how to evaluate DST (see There is a need to create a structured interview the previous discussion of LDL measurement), and a questionnaire oriented to detect the assess its severity, and discriminate between the presence and assess the severity of misophonia. presence and relative contribution of hyper- LDLs are useful for evaluating the poten- acusis and misophonia. Only two question- tial presence of hyperacusis. Normal LDL naires have been published that assess the values (100-dB HL18) exclude the presence extent of hyperacusis: the Hyperacusis Ques- of hyperacusis. As low LDL values could be due tionnaire44 and the Multiple-Activity Scale for to misophonia, the presence of low values alone Hyperacusis (MASH).45 does not provide sufficient proof that the pa- There are some concerns regarding the tient has hyperacusis. Notably, hyperacusis and specificity and selectivity of these question- misophonia frequently occur together. Indeed, naires. The Hyperacusis Questionnaire was misophonia is inevitable in cases of severe created by testing the general population of hyperacusis, as the negative reaction evoked subjects who did not complain of hyperacusis. by hyperacusis will provide negative reinforce- The questionnaire primarily focuses on the ment and create a conditioned reflex linking psychological and social aspects of hearing specific sounds with something negative. Mi- rather than on hyperacusis per se. Indeed, sophonia, however, does not induce only 4 of 14 questions are related to hyperacusis hyperacusis. whereas the remaining questions are related to LDL values reflect the contribution of other aspects of hearing, including hearing loss hyperacusis and misophonia. The goal is to (for example, “5. Do you have difficulty listen- obtain LDLs that reflect hyperacusis and mini- ing to conversations in noisy places?”).44 The mize the contribution of misophonia. Typically, MASH questionnaire consists of a list of 14 the misophonic component is enhanced by activities, and respondents are asked to indicate patients’ concern that they will be exposed to their level of annoyance related to a given a loud sound that would make their tinnitus activity on a scale from 0 to 10.45 Although and/or DST worse; unfortunately, this may both questionnaires have been reported to be reflect the past experience of some patients. effective in evaluating hyperacusis, interesting- To decrease the impact of misophonia on ly, there was no correlation of their scores with LDLs, we promote a modification of the stan- audiological measurements of discomfort levels dard procedure for administering LDLs.48 Pa- such as the LDL test and a speech discomfort tients are given the full power to stop the LDL level assessment.45 Therefore, these question- test at any time. In addition, patients are DECREASED SOUND TOLERANCE/JASTREBOFF AND JASTREBOFF 113 presented with short beeps of sound separated used.13,54 Pink noise therapy as proposed by by a second or more of silence, so they have time Vernon and Press has gained some recogni- to think and decide if they will allow for a tion.13 For this protocol, patients are advised to further increase of the sound level.3,49 LDL stop overprotecting their ears and to listen to measurements are administered twice and the pink noise through headphones set at the high- second set of results is used to assess the est comfortable level for 2 hours a day. A group potential presence of hyperacusis. Note that of patients were provided with pink noise misophonic patients tend to have higher cassette tapes, and questionnaires were mailed LDL values during the second test. For exam- to 30 participants. Of 20 patients who re- ple, the first set of values may be 85-, 90-, 85-, sponded, 13 reported using these tapes in a and 80-dB HL for 1, 3, 4, and 6 kHz, respec- systematic manner and 7 (54%) reported im- tively, and the second set may be 90-, 95-, 90-, provement in their hyperacusis.13 A version of and 90-dB HL, respectively. pink noise therapy also has been proposed In cases of pure hyperacusis, LDLs are in recently for tinnitus and hyperacusis by John- the 60- to 85-dB HL range.4 In cases of pure son.55 The protocol combines the use of pink misophonia, LDL values as low as 30-dB HL to noise with a 16-week cognitive exercise pro- as high as 120-dB HL can be observed. There- gram, divided into sections and devoted to fore, LDLs alone are insufficient to diagnose different topics, such as recognition and relief. hyperacusis or misophonia and a specific, de- To date, no results have been published in the tailed interview is crucial to diagnose and assess peer-reviewed literature regarding the effec- the relative contribution of hyperacusis and tiveness of this approach. misophonia to DST. Medications have been recommended for DST aimed at decreasing anxiety, depression, and other negative reactions. Cognitive behavior- TREATMENT OF HYPERACUSIS al therapy (CBT) has been proposed as well.56 AND MISOPHONIA There are no reports in the literature showing the There are very limited data in the literature on positive effects of medication on DST (except for the results of hyperacusis treatment. According migraine) and there is limited information on the to anecdotal reports, treatment has taken two efficacy of CBT to treat DST.57 opposite directions. The most common ap- In rare cases of hyperacusis, exposure to proach is to advise patients to avoid sound normal, everyday sound can evoke vestibular and use ear protection. This approach is based disturbances (e.g., sound-induced loss of bal- on the reasoning that because patients became ance, a feeling of motion sickness, nausea, sensitive to sound, they are supposedly more vertigo, or dizziness). This is called the Tullio susceptible to sound exposure and consequently phenomenon (sometimes vestibular hyperacusis), require extra protection. Patients readily em- and it is one of the common symptoms of brace this advice and begin to protect their ears, superior canal dehiscence syndrome and may even to the extent of using earplugs in quiet be successfully treated by . environments. Unfortunately, this well-in- As discussed previously, hyperacusis results tended approach makes the auditory system from enhanced gain within the auditory system, even more sensitive to sound and further ex- particularly the central part of the auditory acerbates hyperacusis.13,50–53 pathways. The sensory systems work according The opposite approach to treating hyper- to the principle of automatic gain control; acusis involves desensitization wherein patients depending on the strength of the signal, the are exposed to a variety of sounds. The desen- sensitivity and gain changes continuously. Con- sitization approach has been promoted for some sequently, the lack of sensory input results in an time with several protocols and types of sounds increase of gain within the auditory system, used.13 For example, sounds with certain fre- yielding a corresponding enhancement of neu- quencies removed, short exposure to moderate- ronal activity representing a sound, whereas ly loud sound, or prolonged exposure to exposure to louder sound yields a decrease in relatively low-level sounds have been gain. Therefore, according to the principles of 114 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

the neurophysiological model of tinnitus, as sound that is not annoying to them, even when well as the proposed mechanisms of hyper- listening to the sound for many hours. At the acusis, the systematic enhancement of the pa- same time, patients should be able to easily tient’s auditory background should result in notice the sound when focusing their attention decrease of the gain within the auditory path- on it. Patients may temporarily increase the ways. Consequently, this approach is recom- sound level when going to louder places. mended and used as part of Tinnitus Retraining Independent studies support the use of TRT Therapy (TRT). for the treatment of hyperacusis and have shown that the desensitization approach used in TRT has a statistically and clinically significant impact IMPLEMENTATION on hyperacusis.53,63 It is possible to observe When TRT is used to treat hyperacusis, specific significant improvement in hyperacusis and im- counseling is provided with the focus on the provements in LDLs within a few months. In proposed mechanisms of hyperacusis, auditory some cases, it is possible to achieve a cure for and toughening (i.e., preexposure to a nondamaging elimination of hyperacusis. level of noise provides protection against loud As discussed previously, the mechanisms of noise58–60), and sound therapy.2,3 Sound en- misophonia and hyperacusis are very different. richment can be achieved by various means, In the case of misophonia, because the auditory with tabletop sound machines and ear-level system works within the norm, the misophonic sound devices (i.e., sound generators or combi- component of DST cannot be removed by nation devices that feature amplification and a classical desensitization therapy. A different sound generator) being most common. The approach must be used for misophonia that sound used in sound therapy for hyperacusis includes specific counseling and therapy involv- cannot evoke annoyance or other problems for ing several specific protocols of sound use.3–5,64 any reason, as the negative activation of the As misophonia results from enhanced function- limbic and autonomic nervous systems would al connections between the auditory and the then occur, which, in turn, enhances condi- limbic and autonomic nervous systems, which tioned reflexes and, as a consequence, enhances are governed by principles of conditioned re- negative reactions to sound. flexes, treatment for misophonia is aimed at The sound emitted by the wearable sound weakening and then removing these connec- generators should be set at or above a level tions using protocols appropriate for the extinc- below which stochastic resonance (i.e., en- tion of conditioned reflexes. Specifically, the hancement of the signal by adding low-level active extinction of conditioned reflexes is per- broadband noise) could be evoked (i.e., 6-dB formed by linking currently offensive sounds sensational level (SL) or higher).61 At the same with something positive. Note the similarity time, the sound should not be too high as to between the mechanisms of misophonia and make it difficult to understand speech (above tinnitus. The difference is in the initial signal 20-dB SL). Stochastic resonance might en- (internally generated neuronal activity in the hance a loudness match of coexisting tinnitus case of tinnitus and neuronal activity evoked by by 10%,61 and anecdotal reports indicate the an external sound for misophonia), but the possibility of inducing tinnitus in patients remaining proposed mechanisms are the treated with sound generators set close to same. Consequently, treatment for misophonia threshold of a patient hearing. usually takes a similar amount of time as the Our results show that, on average, hyper- treatment for tinnitus. acusis patients use sound at 9-dB SL (range When hyperacusis and misophonia coexist, from 0 to 20 dB SL) as evaluated by real ear offensive sound evokes the overactivation of measurement.62 There is no need to initially set neuronal activity within the auditory pathways; the sound to a lower level, nor are patients asked in turn, this signal is further enhanced while to change the sound level of the devices in a conveyed to the limbic and autonomic nervous systematic manner during treatment.62 In prac- systems via connections that are tuned to the tical terms, it is recommended that patients use specific pattern of the sound. Clinical DECREASED SOUND TOLERANCE/JASTREBOFF AND JASTREBOFF 115 observations indicate that even when coexisting and adjusts the sound level to a volume that is hyperacusis is treated successfully, as shown by optimal for listening pleasure. Before beginning changes in LDLs to normal values, the behav- the listening session, the patient is then asked to ioral reactions of patients remain the same in increase the volume by a just noticeable differ- that patients do not perceive improvement. ence. In practice, the increase in volume will be Presumably, misophonia becomes even stron- 2 dB or a little more. During the third week, ger, which keeps the strength of the negative the patient is asked to increase the initial reactions the same. optimal level by 2 steps, which would yield a For misophonic patients, the sound therapy volume increase of 4to5dB. component includes the same recommendations This protocol has two goals: (1) to create a as for hyperacusis. However, specific additional positive association with a favorite type of sound protocols for sound use are recommended. and (2) to gradually increase the level of sound There are four classes of sound protocols for considered to be optimal. Due to the principle of misophonia and all of them contain a compo- stimulus generalization, the positive associations nent whereby positive associations are formed that are formed will spread to include other, with sound. The protocols differ in terms of the similar types of sound. This protocol is completely extent of control the patient has over the safe, as the patient fully controls the type, level, environment, the sounds used, and the length and duration of sound he or she is listening to. of exposure. Additionally, for protocol category Protocol category 1 is not aimed at exposing the 4, complex conditioned stimuli are created by patient to a variety of sounds or to offensive combining offensive sounds with sounds that sounds, but at creating a positive association have highly positive connotations, and then with sound in general. In cases of coexisting gradually modifying the relative levels of those hyperacusis, this is the only protocol used. two types of sound. Notably, the protocol must Protocol category 2 also provides the pa- be tailored to the individual. Frequently more tient with full control over the type of sound than one protocol is used concurrently. used (e.g., music, movie, TV program), but only Protocol category 1 provides the patient with partial, indirect control over the sound level. In full control over the selection of sound used, its this case, control is given to someone close to level, and its duration.4 This protocol can be used the patient who is instructed to set the sound even in cases of coexisting significant hyperacusis volume to a level he or she thinks the patient from the beginning of DST treatment. will accept. After a listening session, the patient When implementing this protocol, pa- should provide feedback as to whether the tients are asked to select a sound they like sound level was too high, too low, or just very much and listen attentively to it once or fine, so that the individual can adjust the level twice a day for 15 to 30 minutes each time. for the next session. Patients typically select music, but any favorite The following example shows a movie sound can be used such as an audiobook on CD being used to implement this protocol. Patients or a favorite TV show (particularly in the case of are asked to select one of their favorite movies children). In the following example, music will and watch it in its entirety on DVD (or be used. The specific music selected for a given download it from the Internet) one to two day can vary depending on what the patient times a week. Patients should select a movie feels like listening to at a given moment. It is they feel like watching at a given time. The important that the patient listen attentively to sound level is set by somebody living with the the music and is not involved in any other patient, but modified from session to session on activity that requires his or her attention (e.g., the basis of feedback from the patient. Patients the patient should not read a book at the same who use sound generators or combination de- time or drive a car). During the first week, every vices are advised to increase the sound level of session begins with the patient selecting music the generators before starting the movie.3 and then adjusting the sound level to achieve This protocol also creates a positive associ- maximum pleasure. During the second week, ation with sound, but decreases the patient’s the patient selects music he or she wants to hear direct control over the sound level. As the 116 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

average movie contains a variety of sounds, bothersome to a patient than the sounds of patients will attain a more positive association eating at home, the protocol should first be with several sounds because they are presented implemented at school. The multisensory aspect while the patient is enjoying the movie. of stimuli also is taken into account as some Protocol category 3 enables the patient to patients react even to seeing someone produce select the type of sound, but the sound level is offensive sounds (e.g., eating). Consequently, outside his or her control. This protocol is patients are advised to observe offensive situa- aimed at exposing the patient to a variety of tions while listening to highly positive sounds. sounds encountered in everyday life and there- An example of implementation: Let’s as- fore going to a movie theater is recommended. sume that a patient strongly reacts to the sounds For some patients, it is recommended that they of eating when at home. In this case, the patient go to shopping malls and gradually visit louder is asked to select a highly favorable sound, such stores. This protocol is used only when signifi- as music he or she likes a lot. In the first stage of cant hyperacusis is absent or has been eliminat- this protocol, before the meal, the patient is ed by treatment. (Patients can always choose to asked to start playing the music at a level that leave a noisy environment when annoyed by still allows the offensive sounds to be heard. An sound or for any other reason.) open-field sound presentation is preferred, as When implementing this protocol, pa- headphones or earbuds will isolate patients tients are asked to go to a movie theater once from other people, but if the type of music or or twice a week and select only their most its level is unacceptable to others, then head- favorite movies. Patients who use sound gen- phones or earbuds are recommended, provided erators or combination devices are advised to the patient can still hear the offensive sounds. increase the sound level of the generators before Typically, it is recommended that the positive entering the movie theater. If the situation sound should not mask the offensive sounds; causes strong discomfort, the patient should however, full masking is permitted for a limited leave the theater and return 10 to 15 minutes time for those patients who exhibit an extremely later. strong reaction to the offensive sounds. This protocol works similarly to protocol After the patient follows this protocol for category 2 but removes patients’ control over 1 week, and provided the newly created com- the sound level to which they are exposed. It plex stimulus has a positive or neutral connota- creates a positive association with a broad tion for the patient and is well tolerated, the variety of sounds even when some sounds are level of positive sound is gradually decreased presented at a typically high level. over a period of weeks to months. Protocol category 4 is more complex and Protocol category 4 is applied to all offen- addresses specifically offensive sounds. It imple- sive sounds; if it is difficult to create a situation ments the concept of complex conditioned with certain offensive sounds, the sounds can be stimuli, which are created by combining offen- recorded and played back to create the complex sive sounds with sounds that have highly posi- stimulus described previously. Furthermore, to tive connotations, and then gradually modifying facilitate treatment, stimuli from other sensory the relative levels of the two types of sound. modalities in addition to sound (i.e., vision, Once the new complex stimulus is established, taste, smell), which are associated with positive the ratio of positive to negative sound is gradu- emotions and have some connection with the ally decreased. The environment where this offensive sound, are introduced. For example, if protocol is used must be taken into account, the crunching sound of a cookie as it is being as many patients react differently depending on eaten is aversive to a patient but the patient likes where they are exposed to a bothersome sound to eat cookies, the smell of freshly baked cookies (i.e., home, school, a restaurant, a friend’s is presented at the same time the crunching home). Patients are advised to start with less sound is made. offensive sounds and gradually work with more Some “desensitization protocols” resemble challenging sounds and situations. For example, a simplified version of protocol category 4. if the sounds in a school cafeteria are less However, protocol category 4 appears to be DECREASED SOUND TOLERANCE/JASTREBOFF AND JASTREBOFF 117 more powerful and consistent in offering help misophonia (33 of 39, or 85%) and lower for to patients even in challenging cases, such as for patients with hyperacusis alone (13 of 17, or autistic children, perhaps because it is based on 76%). The effectiveness of treatment for miso- specific postulated neurophysiological mecha- phonia with or without hyperacusis was identi- nisms and on well-established methods from cal (152 of 184 patients with misophonia behavioral psychology.43 accompanied by hyperacusis, or 83%, and 139 of 167 patients with misophonia alone, or 83%). In some cases, it is possible to achieve a cure RESULTS OF TREATMENT OF for misophonia, as is also the case for hyper- HYPERACUSIS AND MISOPHONIA acusis.5,65 Furthermore, our clinical observa- AT EMORY TINNITUS AND tions demonstrated that treatment of HYPERACUSIS CENTER misophonia is crucial to achieving a successful Detailed information was available for 201 outcome for tinnitus treatment.66 consecutive patients diagnosed with DST. Of these 201 patients, 184 (92%) exhibited miso- phonia; 17 patients (8%) had hyperacusis alone, SUMMARY AND CONCLUSIONS and 56 patients (28%) had hyperacusis and DST remains a complex and elusive phenome- misophonia concurrently. The proportion of non that has only recently attracted larger patients with significant hyperacusis (with or attention. There is limited information on without misophonia) who required specific epidemiology, potential mechanisms, and re- treatment is similar to the 25 to 30% reported sults of a variety of treatments that are used. in the literature3,21–24 and to the 26% we have The situation is particularly complex and diffi- reported previously.4 cult with misophonia (reaction to specific pat- All patients were treated with an appropri- terns of sound). Consequently, many patients ate version of TRT. The initial and follow-up with DST are left without help. The proposed structured interviews were used to monitor the mechanisms of hyperacusis and misophonia, treatment, with several questions aimed at which are based on the neurophysiological assessing DST. Patients were asked to judge model of tinnitus, indicated a potential ap- the severity of their DST, the annoyance in- proach to their treatment. These treatments duced by it, the effect of DST on their lives, and have been used for over a decade as part of TRT to rate DST as a problem on a scale from 0 to 10 with a high level of success for both hyperacusis (where 0 corresponded to an absence of DST and misophonia. This observation supports the and 10 indicated DST was as big of a problem as proposed mechanisms of DST. There is still they could imagine). Patients were asked to need for improvement in the diagnosis and consider an average over the last month in their treatment of DST, as well as for research that responses. could lead to a better understanding of the Improvement in hyperacusis was judged on problem. the basis of changes in LDLs combined with responses obtained during the structured inter- REFERENCES views, whereas improvement in misophonia was solely based on the interviews. This decision 1. Baguley D, McFerran D. Hyperacusis and disor- was based on the observation that in cases of ders of loudness perception. In: Moller A, Klein- misophonia, any LDL values could be seen and jung T, Langguth B, De Ridder D, eds. Textbook that the values were not correlated with pa- of Tinnitus. New York, NY: Springer; 2010:13–23 tients’ judgment of the problems due to DST. 2. Jastreboff PJ, Hazell JWP. Tinnitus Retraining Of 201 patients with DST, 165 patients Therapy: Implementing the Neurophysiological (82%) showed significant improvement. For 56 Model. Cambridge, UK: Cambridge University Press; 2004 patients with hyperacusis (with or without 3. Jastreboff PJ, Jastreboff MM. Decreased sound misophonia), 45 patients (80%) showed signif- tolerance. In: Snow JB, ed. Tinnitus: Theory and icant improvement. This proportion was higher Management. London, UK: BC Decker; 2004: for the group with hyperacusis and concurrent 8–15 118 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

4. Jastreboff MM, Jastreboff PJ. Decreased sound 20. Klein AJ, Armstrong BL, Greer MK, Brown FR tolerance and Tinnitus Retraining Therapy III. Hyperacusis and otitis media in individuals (TRT). Aust N Z J Audiol 2002;21(2):74–81 with Williams syndrome. J Speech Hear Disord 5. Jastreboff PJ, Jastreboff MM. Using TRT to treat 1990;55(2):339–344 hyperacusis, misophonia and phonophobia. ENT 21. Hazell JWP, Sheldrake JB, Graham RL. Decreased Audiology News 2013;21(6):88–90 sound tolerance: predisposing / triggering factors 6. Jastreboff MM, Jastreboff PJ. Hyperacusis. Audi- and treatment outcome following tinnitus retrain- ology On-line 6–18–2001. Available at: http:// ing therapy (TRT). Paper presented at: 7th www.tinnitus.org/DST_NL2_PJMJ.pdf. Accessed International Tinnitus Seminar; March 5–9 2002; on March 19, 2014 Fremantle, Western Australia; Perth, Australia: 7. Jastreboff PJ. Tinnitus Retraining Therapy. In: University of Western Australia.255–261 Moller A, Kleinjung T, Langguth B, De Ridder D, 22. Herra´iz C, Plaza G, Aparicio JM. [Mechanisms eds. Textbook of Tinnitus. New York, NY: Spring- and management of hyperacusis (decreased sound er; 2010:575–596 tolerance)]. Acta Otorrinolaringol Esp 2006;57(8): 8. Jastreboff PJ, Jastreboff MM. Tinnitus and de- 373–377 creased sound tolerance. In: Ballenger JJ, Snow JB, 23. Herra´iz C, Herna´ndez Calvı´n J, Plaza G, Toledano Ashley WP, eds. Ballenger’s A, de los Santos G. [Study of hyperacusis at a Head and Neck Surgery. 17 ed. San Diego, CA: tinnitus unit]. Acta Otorrinolaringol Esp 2003; Singular Publishing; 2009:351–362 54(9):617–622 9. Schro¨der A, Vulink N, Denys D. Misophonia: 24. Jastreboff PJ, Jastreboff MM, Sheldrake JB. Audio- diagnostic criteria for a new psychiatric disorder. metrical characterization of hyperacusis patients PLoS ONE 2013;8(1):e54706 before and during TRT. In: Hazell JWP, ed. 10. Fabijanska A, Rogowski M, Bartnik G, Skarzynski Proceedings of the Sixth International Tinnitus H. Epidemiology of tinnitus and hyperacusis in Seminar. Cambridge, UK THC1999:495–498 Poland. In: Hazell JWP, ed. Proceedings of the 25. Anari M, Axelsson A, Eliasson A, Magnusson L. Sixth International Tinnitus Seminar. Cambridge, Hypersensitivity to sound—questionnaire data, UK: THC; 1999:569–571 audiometry and classification. Scand Audiol 11. Baguley DM. Hyperacusis. J R Soc Med 2003; 1999;28(4):219–230 96(12):582–585 26. Hoffman HJ, Reed GW. Epidemiology of tinnitus. 12. Andersson G, Lindvall N, Hursti T, Carlbring P. In: Snow JB, ed. Tinnitus: Theory and Manage- Hypersensitivity to sound (hyperacusis): a preva- ment. London, UK: BC Decker; 2004:16–41 lence study conducted via the Internet and post. Int 27. Baguley D, Andersson G. Hyperacusis Mecha- J Audiol 2002;41(8):545–554 nisms, Diagnosis, and . San Diego, 13. Vernon J, Press L. Treatment for hyperacusis. In: CA: Plural Pub; 2007;144; Vernon JA, ed. Tinnitus Treatment and Relief. 1st 28. Niu Y, Kumaraguru A, Wang R, Sun W. Hyper- ed. Boston, MA: Allyn & Bacon; 1998:223–227 excitability of inferior colliculus neurons caused by 14. Byrne D, Dirks D. Effects of acclimatization and acute noise exposure. J Neurosci Res 2013;91(2): deprivation on non-speech auditory abilities. Ear 292–299 Hear 1996;17(3):29S–37S 29. Sahley TL, Nodar RH. A biochemical model of 15. Cox RM, Alexander GC, Taylor IM, Gray GA. peripheral tinnitus. Hear Res 2001;152(1–2):43–54 The contour test of loudness perception. Ear Hear 30. Marriage J, Barnes NM. Is central hyperacusis a 1997;18(5):388–400 symptom of 5-hydroxytryptamine (5-HT) dys- 16. Hawkins DB, Walden BE, Montgomery A, Prosek function? J Laryngol Otol 1995;109(10):915–921 RA. Description and validation of an LDL proce- 31. Gopal KV, Daly DM, Daniloff RG, Pennartz L. dure designed to select SSPL90. Ear Hear 1987; Effects of selective serotonin reuptake inhibitors on 8(3):162–169 auditory processing: case study. J Am Acad Audiol 17. Ricketts TA, Bentler RA. The effect of test signal 2000;11(8):454–463 type and bandwidth on the categorical scaling of 32. Jastreboff PJ, Hazell JWP. A neurophysiological loudness. J Acoust Soc Am 1996;99(4 Pt 1): approach to tinnitus: clinical implications. Br J 2281–2287 Audiol 1993;27(1):7–17 18. Sherlock LP, Formby C. Estimates of loudness, 33. Attias J, Zwecker-Lazar I, Nageris B, Keren O, loudness discomfort, and the auditory dynamic Groswasser Z. Dysfunction of the auditory efferent range: normative estimates, comparison of proce- system in patients with traumatic brain injuries dures, and test-retest reliability. J Am Acad Audiol with tinnitus and hyperacusis. J Basic Clin Physiol 2005;16(2):85–100 Pharmacol 2005;16(2–3):117–126 19. Blomberg S, Rosander M, Andersson G. Fears, 34. Baguley DM, Axon P, Winter IM, Moffat DA. hyperacusis and musicality in Williams syndrome. The effect of vestibular nerve section upon tinnitus. Res Dev Disabil 2006;27(6):668–680 Clin Otolaryngol Allied Sci 2002;27(4):219–226 DECREASED SOUND TOLERANCE/JASTREBOFF AND JASTREBOFF 119

35. Scharf B, Magnan J, Chays A. On the role of the 51. Formby C, Hawley M, Sherlock LP, et al. Inter- olivocochlear bundle in hearing: 16 case studies. vention for restricted dynamic range and reduced Hear Res 1997;103(1–2):101–122 sound tolerance: clinical trial using a Tinnitus 36. Jastreboff PJ. Phantom auditory perception (tinni- Retraining Therapy protocol for hyperacusis. J tus): mechanisms of generation and perception. Acoust Soc Am 2013;133(5):3382–3383 Neurosci Res 1990;8(4):221–254 52. Hawley ML, Keaser ML, Formby C. Predicting 37. Boettcher FA, Salvi RJ. Functional changes in the hyperacusis in tinnitus patients. Semin Hear 2007; ventral cochlear nucleus following acute acoustic 28(4):261–275 overstimulation. J Acoust Soc Am 1993;94(4): 53. Formby C, Gold SL, Keaser ML, Block KL, Hawley 2123–2134 ML. Secondary benefits from Tinnitus Retraining 38. Gerken GM. Alteration of central auditory proc- Therapy: Clinically significant increase in loudness essing of brief stimuli: a review and a neural model. discomfort level and expansion of the auditory dy- J Acoust Soc Am 1993;93(4 Pt 1):2038–2049 namic range. Semin Hear 2007;28:227–260 39. Noren˜a AJ, Farley BJ. Tinnitus-related neural 54. Jastreboff PJ, Jastreboff MM. Tinnitus Retraining activity: theories of generation, propagation, and Therapy (TRT) as a method for treatment of centralization. Hear Res 2013;295:161–171 tinnitus and hyperacusis patients. J Am Acad 40. Jastreboff PJ. The role of subconscious pathways in Audiol 2000;11(3):162–177 tinnitus and decreased sound tolerance. Paper 55. Johnson M. Pink sound protocol for tinnitus & presented at: 9th International Tinnitus Seminar; hyperacusis. Available at: http://www.pinksound. June 15–18 2008; Goteborg, Sweden info/. Accessed: January 7, 2014 41. Edelstein M, Brang D, Rouw R, Ramachandran 56. Andersson G, Ju¨ris L, Kaldo V, Baguley DM, VS. Misophonia: physiological investigations and Larsen HC, Ekselius L. [Hyperacusis—an unex- case descriptions. Front Hum Neurosci 2013;7:296 plored field. Cognitive behavior therapy can relieve 42. Klochoff I. Impedance fluctuation and a “Tensor problems in auditory intolerance, a condition with Tympani Syndrome”. Penha R, Pizarro P, eds. many questions]. Lakartidningen 2005;102(44): Paper presented at: Proc 4th International Sympo- 3210–3212 sium on Acoustic Impedance Measurements; 57. Hiller W, Haerko¨tter C. Does sound stimulation September 25–28 1979. Lisbon, Portugal: Univer- have additive effects on cognitive-behavioral treat- sidad Nova de Lisboa; 69–76 ment of chronic tinnitus? Behav Res Ther 2005; 43. Konorski J. Conditioned Reflexes and Neuronal 43(5):595–612 Organization. Cambridge, UK: Cambridge Uni- 58. Henselman LW, Henderson D, Subramaniam M, versity Press; 1948 Sallustio V. The effect of “conditioning” exposures 44. Khalfa S, Dubal S, Veuillet E, Perez-Diaz F, on hearing loss from impulse noise. Hear Res 1994; Jouvent R, Collet L. Psychometric normalization 78(1):1–10 of a hyperacusis questionnaire. ORL J Otorhino- 59. Niu X, Tahera Y, Canlon B. Protection against laryngol Relat Spec 2002;64(6):436–442 acoustic trauma by forward and backward sound 45. Dauman R, Bouscau-Faure F. Assessment and conditioning. Audiol Neurootol 2004;9(5): amelioration of hyperacusis in tinnitus patients. 265–273 Acta Otolaryngol 2005;125(5):503–509 60. Niu X, Tahera Y, Canlon B. Environmental en- 46. Jastreboff MM, Jastreboff PJ. Questionnaires for richment to sound activates dopaminergic path- assessment of the patients and treatment outcome. ways in the auditory system. Physiol Behav 2007; In: Hazell JWP, ed. Proceedings of the Sixth 92(1–2):34–39 International Tinnitus Seminar. Cambridge, UK: 61. Jastreboff PJ, Jastreboff MM. Potential impact of THC. 1999:487–490 stochastic resonance on tinnitus and its treatment. 47. Henry JA, Jastreboff MM, Jastreboff PJ, Schechter Association for Research in Otolaryngology Feb- MA, Fausti SA. Guide to conducting tinnitus ruary 23, 2000. Meeting materials, pg. 5542 retraining therapy initial and follow-up interviews. 62. Jastreboff PJ, Jastreboff MM, Payne L. Real ear J Rehabil Res Dev 2003;40(2):157–177 measurements in tinnitus retraining therapy. Paper 48. Hood JD, Poole JP. Tolerable limit of loudness: its presented at: 7th International Tinnitus Seminar; clinical and physiological significance. J Acoust Soc March 5–9 2002; Freemantle, Australia Am 1966;40(1):47–53 63. Formby C. Hyperacusis and related sound toler- 49. Jastreboff PJ, Gray WC, Gold SL. Neurophysio- ance complains: differential diagnosis, treatment logical approach to tinnitus patients. Am J Otol effects, and models. Semin Hear 2007;28:227–259 1996;17(2):236–240 64. Jastreboff MM. Sound therapies for tinnitus man- 50. Formby C, Sherlock LP, Gold SL. Adaptive agement. In: Langguth B, Hajak G, Kleinjung T, plasticity of loudness induced by chronic attenua- Cacace A, Moller A, eds. Tinnitus: Pathophysiol- tion and enhancement of the acoustic background. J ogy and Treatment. Amsterdam, the Netherlands: Acoust Soc Am 2003;114(1):55–58 Elsevier; 2007:449–454 120 SEMINARS IN HEARING/VOLUME 35, NUMBER 2 2014

65. Jastreboff PJ, Jastreboff MM. Tinnitus Retraining 66. Jastreboff PJ, Jastreboff MM. Decreased Sound Therapy. In: Baguley D, ed. Perspectives in Tinni- Tolerance (Hyperacusis and Misophonia): Theory tus Management. New York, NY: Thieme; 2001: and Clinical Practice. Boston, MA: American 51–63 Academy of Audiology; 2012