Section V. Resonance and Phonation

SAMUEL G. FLETCHER, Ph.D. (CHAIRMAN)

Despite an ever widening scope of topics use of instrumentation and procedures to in cleft research, progress in reha- increase diagnostic and management pre- bilitation is still largely defined by the ex- cision, and (c) systematic evaluation of tent to which speech disorders exist, may «speech treatment restults. The importance be prevented, or are eradicated (Bauer, of multistructural dynamic impairment 1972; Randal, 1974; Kraus, VanDemark, - has also been mentioned frequently but and Tharp, 1975; Wilder and Baken, has received little direct attention. 1975). In the speech section of the previous Palatopharyngeal Disturbance Without state-of-the-art review (Spriestersbach et Overt Cleft al., 1973) major attention was given to Identification of palatopharyngeal dis- three broad aspects of speech research: 1) turbance in the absence of overt cleft disturbances in anatomical and physiologi- serves to highlight a variety of disorders cal aspects of speaking; 2) assessment of with potentially common speech symptom- special speech characteristics and disor- atology. Calnan (1976) recently re-pre- ders attributable to maxillofacial anomaly; sented his system for classifying such dis- and 3) therapeutic processes and proce- turbances. Minami and associates (1975) dures for speech habilitation. A number of proposed an expanded etiological classifi- issues identified in the earlier review re- cation system in which nearly fifty types of main unresolved. For example, informa- disability known to affect palatopharyn- tion is still unavailable concerning a variety geal structure and function are itemized. of essential components of velopharyngeal They also reviewed observations from 188 (V-P) movement in speakers with V-P in- patients and attempted to differentiate eti- sufficiency. These include a description of ological indices, certain speech characteris- the distribution of forces impinging upon tics, and appropriate surgical management the velopharyngeal valve during normal as a function of disability type. Such infor- and impaired speaking, physiologic pat- mation provides an excellent foundation terns of altered velar function as a conse- for definitive documentation of speech quence of and other forms signs, disorders, and incidence of impair- of surgical intervention, and modifications ment among patients with the heteroge- in sound transmission occurring in re- neous disabilities. sponse to partial-to-complete obstruction Several papers have appeared recently of the nasal passageways and associated that provide information about aspects of disturbances in V-P valving. palatopharyngeal function that have been Three major concerns appear in the given little prior attention. Gibb and Stew- forefront of speech resonance and phona- art (1975) described a patient with "hysteri- tion research during the 1972-1976 period: cal" hypernasality following simple tonsil (a) incidence and characteristics of defi- dissection. Adenoridectomy was not per- ciencies in palatopharyngeal structure formed. They suggested that the possibil- without overt cleft, (b) development and ity of emotional reactions should be con- sidered when organic impairment cannot Dr. Fletcher is Professor of Biocommunication, be firmly established. Dentistry and Rehabilitation Medicine, Chairman, Messengill, Pickerel and Robinson Biocommunication Department, University of Ala- bama in Birmingham, P.O. Box 187, University Sta- (1973) observed that some patients with tion, Birmingham, Alabama 35294. submucosal cleft palate (SMCP) do not 313 314 Cleft Palate Journal, October 1977, Vol. 14 No. 4

have hypernasal speech. However, in their through study of such patients appears opinion, patients of this type are few in promising. number. The low incidence claim was re- cently challenged by Porterfield, Mohler, Vocal Tract Functions Related to Cleft and Sandel (1976) who reported that 18 of Palate ’ 97 patients they identified with SMCP had The introduction of new instrumenta- normal speech. tion brings opportunity to re-evaluate cur- An electronic instrument which uses the rent concepts about structural deficiencies principle of translumination to detect mus- and speech performance as well as to in- cular discontinuity in submucous cleft pal- crease the precision of observations being ate has been described by Pawlawski made. In a review of radiographic tech- (1975). The data reported demonstrated niques used to study velopharyngeal func- an ability to distinguish such persons from tion, Skolnick (1975) called particular at- those with normal palatal structure. tention to the three-dimensional, sphinc- Hypernasality is typically identified as a teric valving characteristics of the V -P por- consequence of developmental or disease tal. Drawing upon evidence from a series trauma to velopharyngeal structures. Re- of frontal-, lateral- and basal-view studies, cent advances in facial surgery to correct he and his associates made videoflurosco- retroposition of the maxilla have provided pic observations which provide unique in- an additional opportunity to learn more sight into specific dynamics of V-P action. about the relationships between palato- A system for classifying the spectrum of pharyngeal morphology and nasality. sphincteric patterns from the basal view Schwartz and Gruner (1976) identified orientation supports this thesis. A problem perceptable alterations in nasal resonance of basal view x-ray is the "sphinx" position as a function of surgically changing the used to visualize the soft tissue activities. position of the maxilla and attached soft Shelton and Trier (1976) pointed out that palate. Maxillary advancement was associ- this abnormal posture can influence both ated with a slight to moderate increase in the anatomical relationships of the palato- perceived nasality in 27 of 31 (87%) pa- pharyngeal structures at rest and the sub- tients studied with repaired palatal clefts. sequent motion patterns as the person A small, but identifiable, increase in per- speaks. They also note that the use of ra- ceived nasality was detected in two (22%) diopaque media to define soft tissue of 9 patients with no overt palatal clefts. boundaries has been shown to change There appeared to be little correspond- speech patterns in certain subjects. ence between the extent of maxillary ad- Visualization of sphincteric action of vance and the degree of change in nasality. palatopharyngeal valving similar to that of Using Schwartz and Gruner's data, a cor- basal-view videofluoroscopy may be ob- relation coefficient was calcualted to ex- tained by oral and nasal endoscopy or fi- amine the strength of this association. The beroscopy without the risk of radiation. resultant value (r = .18) was low and non- Willis and Stutz (1972) and Zwitman, Son- significant. A variety of explanations could derman, and Ward (1974) have presented be advanced to account for the intersubject systems for classifying the V-P valving pat- differences in speech degradation follow- terns from oral endoscopy. Piggot and ing maxillary advancement. For example, Makepiece (1975) and Matsuya, Miyazaki, differences in degree of velopharyngeal and Yamaoka (1974) have described V-P competency could have been unmasked by functions from nasal endoscopic and fiber- the- changes in structural morphology. optic viewpoints respectively. Conversely, variation in the strategies used The obvious disadvantage of oral endos- to adapt to the surgically restructured copy is that the instrument lies on or above morphology may have been an important the tongue during examination. This re- factor in the degree of speech degradation stricts the phonetic repertoire for speech found. The potential for gaining new in- observations essentially to low vowels and formation concerning speech adaptation labial consonants. Nevertheless, as shown Fletcher, STATE-OF-ART (RESONANCE) 315 by Zwitman, Gyepes and Ward (1976) the other than those of the velopharyngeal observations which can be made show area. good agreement with those from basal From pneumographic studies Tron- view fluoroscopy. ‘ cyznska (1972) reported that cleft palate While nasal endoscopy and fiberoscopy speakers as a group have a greater fre- yield data on V-P function without the quency of breaths during speech than phonetic restrictions of oral endoscopy, their normal counterparts, and the rate possible changes in physiology from the difference tends to become more exagger- discomfort incident to insertion of the in- ated with speech habilitation. Similar ob- strument through the nasal cavities has not servations with respect to control of the been investigated. airstream were summarized by Warren A serious problem of all endoscopic and (1975) in his recent review of aerodynamic fiberoptic systems for visualizing sphinc- changes related to palatopharyngeal in- teric actions of palatopharyngeal valving is competency. quantification. Present lens systems used Changes in laryngeal function have also in endoscopy have progressive distortion been observed in speakers with palato- from the center of the image (Schwartz, pharyngeal anomalies. McWilliams, La- 1975), and none of the instrumental ap- vorato, and Bluestone (1973) reexamined proaches now available enable specifica- 27 patients approximately five years after tion of the cephalocaudal level at which V - abnormalities of the vocal cords had been P function is being monitored. Use of identified. They found that 70 per cent of multi-element ultrasound tranducers the subjects still demonstrated vocal cord (Skolnick, McCall, and Barnes, 1973) may abnormalities and that 53 per cent of those assist in identifying the region of maxi- speakers showed the same condition as mum motion and thus help resolve ques- found previously. All subjects in this latter tions concerning the cephalocaudaul level group had vocal nodules. They also noted of movements being scrutinized. that hoarse voice quality persisted in eight The main source of speech degradation subjects although the vocal folds no longer associated with palatal clefts is recognized appeared abnormal. to be from residual disturbances in palato- Other evidence of differences in laryn- pharyngeal valving. Despite excellent sur- geal function in the presence of nasaliza- gery, the incidence of speech impairment tion and of assimilated nasality in utter- has remained in the range of 25% (Morris, ances of normal speakers has been pro- 1973). The nature of these remaining dis- vided by Hamlet (1973). She used com- orders is not well understood. Saxman bined ultrasonic and acoustic techniques to (1972) has suggested that aerodynamic and measure the open quotient of the vocal acoustic disturbances resulting from defec- fold vibratory cycle and peak-to-peak am- tive oral-nasal coupling may precipitate plitude of the sound waves. From these secondary reactions in other speech struc- data she observed that, at equal levels tures. He noted that assessment of such of sound intensity, the open quotient of consequences will require multistructural nasalized vowels was comparable to that of observations for adequate documentation.. non-nasalized vowels produced during Ericsson (1973) speculated that compensa- loud phonation. With the degree of mouth tory articulation patterns acquired prior to opening controlled, the difference be- achieving velopharyngeal competence may tween the two modes of speaking was in- interfere with later adaptations in V-P creased. Her conclusion was that "glottal function. Unexplored is the possibility that tightness" evidenced by the reduced open certain intricate coordinations of the laryn- quotient could contribute to hoarseness, geal, oral, and palatopharyngeal struc- harshness and vocal nodules secondary to tures essential to fine control of nasal reso- hypernasality. nance have not been acquired. Such con- An aspect of laryngeal physiology that siderations have led to expanding cleft pal- appears likely to characterize differences ate research to structures of the vocal tract between cleft palate and noncleft palate 316 Cleft Palate Journal, October 1977, Vol. 14 No. 4

speakers is voice onset time (VOT). Zlatin and palate positions (Kent, Carney and and Koenigsknecht (1975) and Kent (1976) Severeid, 1974), microbeam x-ray (Kiri- summarized a series of studies which dem- tani, Itoh, and Fujimura, 1975) and palato- onstrate a clear maturational relationship metry (Fletcher, McCutcheon, and Wolf, in the pattern of VOT. Kent (1976) indi- 1975) provide ways of specifying structural cated that in the first words spoken by positions, motions, and contact patterns children VOT is unimodal. That is, no and may be expected to pave the way to- difference is evident in the timing of voice ward exploring interstructural relation- onset whether the consonant uttered is ships in greater depth than has hitherto voiced or voiceless. Shortly thereafter, the been done. VOT values become bimodal, and the Configuration and patency of the nasal overlap between voiced and voiceless con- airways has received surprisingly little at- sonant ceases. After about eight years of tention as an influence in the patterns of age, VOT is stabilized and remains in the speech production associated with palatal adult pattern. Interactions between anomaly. It seems likely that the lack of changes in laryngeal function associated correspondence between deficiency of ve- with palatal clefts and voice onset time lopharyngeal valving and many of the at- have not as yet been reported. Presum- tributes of speech disturbance may be re- ably, the series of adaptations in vocal tract lated to great variation in anatomical con- functions incident to surgical and develop- figuration and acoustical transmission mental changes in and around the oral and properties of the nasal tracts as suggested pharyngeal cavities would exert a parallel in 1956 by Counihan. influence on fine motor control of the lar- Ultimately, the listener responds to mul- ynx and consequently have a concomittant tiple sources of signal disturbance by a sin- significant effect on the maturation of gle judgment of perceived "nasality." De- VOT. gree of velopharyngeal closure represents The foregoing discussion suggests that only one of a number of potentially altered laryngeal physiology is likely to become a vocal tract properties. Saxman (1972) has vital consideration in future treatment, emphasized that inadequacies of V -P valv- planning, and management for cleft palate ing account for only about 25 per cent of speakers. the total variance in speech proficiency of The morphology and physiology of cleft palate speakers. The recognition of structures in the oral cavity are also inti- multiple vocal tract disturbances has mately associated with proficiency of brought a resurgence of interest in acousti- speech in those with palatal clefts. The cal measurements (Ericsson, Fant, and position of the tongue within the oral cav- deSerpa-Leitao, 1973) which may reflect ity and the extent of mouth opening have a more encompassing assessment of speech direct influence on the degree of nasal production and thereby achieve closer resonance, as shown in studies reviewed by congruence between perceptual observa- Lubker (1975). For example, to counteract tions and instrumental measurements. For the increased acoustic impedance during example, a recent study by Fletcher (1976) the utterance of vowels such as /i/ and /u/ has shown that a ratio of sound emitted with high tongue and close jaw positions, from the nasal and oral cavities within a the is raised higher and specific resonance frequency range agrees achieves tighter contact. . Electromy- closely with judgments of perceived nasal- ographic evidence cited by Lubker sug- ity. Lindqvist and Sundberg (1972) demon- gests additionally that subtle but systematic strated that, when the frontal and nasal differences may exist in velopharyngeal sinuses are included as shunting cavities in valving during production of the conso- a twin tube model of the vocal tract, the nants although such variations has not resonance response curve peaks in the been demonstrated as yet by other obser- range of 400-600 Hz. This frequency vational procedures. New technologies range corresponds with that identified em- such as point parameterization of tongue perically by Fletcher as the region where Fletcher, STATE-OF-ART (RESONANCE) 317 oral and nasal signals of speakers with following a six-month period of sucking varying degrees of nasality contrast maxi- exercises, performed ten minutes per day, mally. velopharyngeal insufficiency was over- Another approach to analysis of nasal come. . and oral signals has been described by Ste- As noted in a brief review by Powers and vens, Kilikow and Willimain (1975). Small, Starr (1974), the validity of the association vibration sensitive accelerometers were at- between muscle exercises and speech has tached on the neck near the larynx and at been increasingly challenged. To test the the external surface of the nose. The neck- hypothesized relationship, they conduced attached sensor was used for later pitch a carefully structured experiment. Four extraction while the one on the nose subjects were chosen who had residual na- served to detect the presence of acoustic sality following original cleft palate sur- coupling between the nasal and oropha- gery and appeared to have the potential ryngeal cavities. Computer aided displays for V-P closure as indicated by oral man- were used to contrast nasal and nonnasal ometry tests. Cephalometric films demon- speech sounds and to indicate . strated such closure was not accomplished Correlations between such measures and during sustained utterance of the vowel /1/ . listener judgments of nasality have not yet The experimental treatment program con- been determined. sisted of blowing, sucking, swallowing, and gagging exercises performed two to four Modification of Nasal Resonance times each day, five days per week, for six An implicit assumption of speech inter- weeks. Post-treatment evaluations immedi- vention is that speech handicapped per- ately after completion of the program and sons have residual potential for improve- six weeks later included V-P gap measure- ment. The degree of such potential and ments and ratings of nasality. The mean the stability of changes anticipated are fur- V-P gap was .75 mm larger immediately ther presumed to be influenced by a vari- after the program and 0.14 mm larger six ety of factors, many of which may not be weeks after the program's conclusion. controllable. As indicated by the review to Mean nasality on a nine-point scale de- this point, such factors include the extent creased 0.13 between the pretest and im- of deviation from a "normal" vocal tract, mediate post-test and 0.06 between the unused physical ability to "compensate" pretest and final post-test. None of these for deviations or deficiencies inspeech differences was significant. Thus, the structures, the accuracy with which im- creditability of the notion that voluntary pairments in structure and function are muscle exercises per se improve V -P closure identified, and the strength of deviant or decrease nasality is seriously challenged speech production patterns. They also in- by the results of this study. clude the person's motivation for changing The capability of a clinician to sense his speech and the precision of sensing and small decrements in nasality and provide timing reinforcement of improvements at- reinforcement at the most propituous mo- tained (Fletcher, 1973). ment has also been challenged (Fletcher, A common approach to treatment of 1973). Spriestersbach et al. (1973) stated speech disabilities related to palatal clefts bluntly that "Velopharyngeal incompet- has been through use of muscle exercises. ence does not appear to be a problem that Such routines have been directed toward can be solved by [speech ] therapy". gaining voluntary control of muscular There is reason to believe that much of functions and increasing the strength, the failure in bringing about systematic bulk and flexibility of the palate. For ex- reduction in excessive nasal resonance may ample, Massengill and Quinn (1974) de- be related to the perceptual difficulties fac- scribed a patient diagnosed as having de- ing clinicians in this task rather than the veloped velopharyngeal inadequacy and inability of a speaker to modify patterns of associated hypernasality incident to regres- nasality. To increase the accuracy of de- sion of adenoidal tissue. They claimed that tecting improvements in velopharyngeal 318 Cleft Palate Journal, October 1977, Vol. 14 No. 4

valving, instrumental procedures have tained through prosthetic obturation. In been increasingly sought. Several investi- many speakers with prolonged velopha- gators have shown results. In the prior ryngeal incompetence, a mild increase in state-of-the-art review a number of instru- the level of nasalance was observed during ments were described which could be used the initial period of adaptation to the pros- to help in assessing speech functions and thesis. This was typically followed by a determining more precisely the nature spontaneous reversal and nasalance was and magnitude of disturbances perceived again reduced toward a more normal by the speech pathologist. During the level. In two speakers, one with congenital 1972-1976 period, increased attention has palatal insufficiency and one with hyper- been given to use of instrumental feedback nasality after original surgery for cleft pal- to assist in modification of disordered ate, nasalance regressed to virtually pre- speech production patterns. prosthesis level. In contrast, little or no Shelton et al. (1975) used videopanen- nasalance regression was observed among doscopic feedback to assist three normal the speakers with surgically acquired pala- speakers in their efforts to gain voluntary tal defects who had once had normal control of palatopharyngeal closure. The speech. The interpretation of these find- speakers were instructed to observe the ings was that the ingrained feedback refer- actions of closure displayed on the video ences of speakers with congenital V-P in- monitor during fixation of the larynx and sufficiency or with insufficiency spanning during gagging then attempt to simulate many years precipitated motor behavior the action consciously. All three subjects that circumvented the prosthetic obtura- were able to do this. tion of the velopharyngeal portal. In most The capability of modifying defective instances, these "compensatory" behaviors velopharyngeal closure on the basis of vis- apparently gradually eroded and nasal- ual feedback has also been claimed by Mi- ance was reduced. That the two speakers yazaki and his associates (1975). They re- with complete nasalance regression had ported that patients with velopharyngeal the physiological capability for normal inadequacy had been benefitted through speech was demonstrated by rapid reduc- use of a fiberoptic instrument connected to tion in nasalance when instrumental feed- a video monitor to visualize the move- back and nasalance shaping procedures ments of their . Formal documenta- were instituted. Stability of the reductions tion of change in V-P valving and associ- achieved and further general improve- ated effects on speech was not provided. ment in the speech proficiency have since The importance of habitual speaking been verified in annual rechecks. patterns as well as accurate feedback has A study of Shprintzen, McCall, and been shown by Fletcher, Sooudi and Frost Skolnick (1975) suggests that the ability of (1974). In a combined prosthesis-acoustic subjects to attain palatopharyngeal closure study, they compared changes in the ratio in non-speech acts may be generalized to of nasal and oral sound in the speech of speech using relatively simple instrumen- four types of subjects: thirteen speakers tal feedback. This viewpoint contrasts with residual hypernasality after primary sharply with the assertion by Moll (1965) cleft palate surgery, twelve with hyperna- that differences in velopharyngeal actions sality following surgery for carcinoma of during blowing and speaking "caste con- palatal structures, four with hypernasality siderable doubt on the validity of using incident to congenital palatal insufficiency . . . blowing activities to develop velopha- without overt clefts, and three with unre- ryngeal closure for speech." In support of paired cleft palates with associated hyper- their viewpoint, Shprintzen, McCall, and nasality. Changes in "nasalance" were Skolnick described three patients with re- measured using TONAR 11 prior to and sidual hypernasality after primary palatal following revisions of speech prostheses. repair and one after secondary pharyngeal Of particular interest was evidence of flap surgery. All had had varying amounts regression in nasalance from the level at- of speech therapy without successful re- Fletcher, sTATE-OF-ART (RESONANCE) 319 duction in their nasality. Multiview fluoro- formal evaluations of changes in speech scopic techniques revealed that V-P clo- were reported. ' sure was achieved during blowing and Finally, several articles have appeared whistling but not speech. A device called a which summarize current practices in "scape scope" was used to provide feed- management of patients with palatopha- back concerning velopharyngeal action ryngeal insufficiency and associated during treatment. Using such feedback speech disorders. These serve to increase the speaker with the recent pharyngeal general awareness and understanding of flap and two of the other three subjects the new knowledge acquired concerning were reported to gain normal velopharyn- structure, function, and speech profi- geal function in conversational speech. Re- ciency. Examples of such articles which tention of the function was verified in a have appeared during the 1972-to-1976 post-treatment evaluation one year later. time period are articles by Morris (1975) A displacement transducer designed for addressed to otolaryngologists and Mason monitoring palatal movements was de- (1973) to pediatricians on postadenoidec- scribed by Moller, Path, Werth, and Chris- tomy hypernasality and by Randall (1974) tensen (1973). By means of a spring tip and Wilder and Baken (1975) to physicians sensor in contact with the oral surface of and dentists respectively on problems and the soft palate, velar elevation was moni- management of "cleft palate speech." tored. The degree of elevation was then detected and indicated to the speaker on References an oscilloscope screen. Benefits of this de- Baurr, H., [Characteristics and phoniatric treatment vice were evaluated in a single-subject ex- of speech disorders caused by cleft palate with spe- cial reference to present day knowledge], Folia periment with a 12-year-old boy whose Phoniat., 24, 387-399, 1972. [Ger.] speech was intelligible but moderately hy- CALNAN, J ., Surgery for Speech. In Recent Advances in pernasal. Lateral still x-rays demonstrated Plastic Surgery. Edinburgh: Churchhill Livingston a two to three mm V-P gap during utter- (pub), p. 39-57, 1976. CoUuNImHAN, D. T., A Clinical Study of the Speech Effi- ances of /u/ and /s/. Following 14 sessions ciency and Structural Adequacy of Operated Adolescent of treatment using this instrument to pro- and Adult Cleft Palate Patients, Unpub. Ph. D. Diss., vide feedback concerning velar movement Univ. Mich., Ann Arbor, p. 204-208, 1956. during production of an isolated /u/ vowel, Ericsson, G., Fant, G., and pESERPA-LEITAO, A., radiographic measurements of velar eleva- Medical applications. A. acoustical and perceptual evaluation of speech training in postoperative cleft tion demonstrated an increase of about 2.5 palate patients, STL-QPSR, p. 25-28, 1973. mm during the period of study. The velo- FirTcHER, S. G., Perceptual skills in clinical manage- pharyngeal gap, however, remained con- ment of nasality, Folia Phoniat., 25, 137-145, 1973. stant indicating that factors other than that FirtcHER, S. G., "Nasalance" vs. listener judgments of nasality, Cleft Pal. J., 13, 31-41, 1976. measured were responsible for persistance FirtTcHER, S. G., McCutTtcxron, M. J., and Wore, M. of the gap. Perceptual judgments of hy- B., Dynamic palatometry, J. Speech Hear. Res., 18, pernasality during utterance of the /u/ re- 812-819, 1975. mained unchanged during the study. FureEtTcHER, S. G., Sooupt, I., and Frost, S. D., Quan- Tudor and Selley (1974) have claimed titative and graphic analysis of prosthetic treatment for "nasalance" in speech, J. Prosth. Dent., 32, 284- "encouraging results" from use of a con- 291, 1974. tact sensing transducer against the oral GBB, A. G., and StEwART, I. A., Hypernasality fol- surface of the soft palate. The sensor was lowing tonsil dissection-hysterical aetiology, J. Lar- positioned so that elevation of the palate yngol. Otol., 89, 779-781, 1975. HamLrtT, S. L., Vocal compensation: An ultrasonic interrupted a small current. The speakers study of vocal fold vibration in normal and nasal were notified when contact ceased by vowels, Cleft Pal. J., 10, 267-285, 1973. means of circuitry which switched off a KrnT, R. D., Anatomical and neuromuscular matu- light. Subjects were encouarged to gain ration of the speech mechanism: Evidence from awareness of the "feel" of the contact, no- acoustic studies, J. Speech Hear. Res., 19, 421-457, 1976. contact states indicated by the instrument KrEnT, R. D., CarnEy, P. J., and SEvEREID, L. R., then to use the resulting sensation in home Velar movement and timing: Evaluation of a model practice sessions. Unfortunately, only in- for binary control, J. Speech Hear. Res., 17, 470-496, 320 Cleft Palate Journal, October 1977, Vol. 14 No. 4

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