This article is republished with permission from Hearing Review

 

By Gail D. Chermak, PhD, Frank E. Musiek, PhD, and Jeffrey Weihing, PhD

In part 1 of this article, the authors presented their perspectives on a number of issues, including the importance of well-defined participants to maximize the validity of research and draw accurate conclusions, the veracity of CAPD as a diagnostic entity, the need to diagnose CAPD on the basis of efficient test batteries that are sensitive to the integrity of the central auditory nervous system rather than questionnaires or patient report, and approaches to minimizeg confounds in diagnosing CAPD. In part 2, the authors focus on the current state of the evidence regarding the gold standard and the research demonstrating the efficiency of individual central auditory tests and central auditory test batteries, the importance of differential diagnosis by a multidisciplinary team to determine the most appropriate, effective, and efficient treatment and management for individuals with CAPD, and the purpose and efficacy of auditory training to improve auditory processes. The authors conclude part 2, citing Dr. James Jerger’s three lines of converging evidence supporting the reality “of a relatively pure auditory perceptual disorder,” and noting Dr. Frank Musiek’s introduction of the term the auditory footprint that reflects the extensive nature of the auditory system.

 

The Gold Standard and the Purpose of Central Auditory Test Batteries

Some have argued that there is no gold standard CAPD diagnostic test battery.4 Consistent with medical terminology, which defines gold standard as a method or procedure that is widely recognized as the best available,59 it is our position that while there might not be a universally accepted gold standard, we have a considerable body of research demonstrating the efficiency of individual central auditory tests and central auditory test batteries based on performance of individuals with confirmed CANS lesions, including such lesions in children.34-38,60,61

It behooves audiologists to fully assess the nature of an individual’s auditory deficits using efficient central auditory tests and test batteries to determine the primary source(s) of those difficulties, be they cognitive, language processing, peripheral hearing loss, CAPD, or other potential sources. While there is some variance in diagnostic criteria (eg, number of tests, number of standard deviations) across US professional association guidelines, this simply reflects the need for additional research with participants with confirmed CAPD, like that conducted by Musiek et al60 and Weihing et al,40 to determine which tests, how many tests, and use of strict or lax criteria lead to the most efficient (ie, sensitive and specific) diagnosis. It would be completely inappropriate to abandon the use of CAPD as a diagnostic entity, as Wilson and Arnott62 proposed, due to the expected variability in diagnosis rates using different criteria and tests, especially when those criteria and/or tests diverge from evidence-based, professional association guidelines. Similarly, it is incongruous to fault CAPD tests because they do not predict listening or reading ability.63

The purpose of the CAPD diagnostic test battery is to identify and categorize auditory impairment or dysfunction, not to predict behavioral or academic deficits that may or may not be directly related to CAPD. Reading and listening are influenced by many variables, some of which are far removed from the auditory domain.64

 

The Role of Patient Report

There have also been suggestions that our field might be wise to dispense with the “CAPD label,” and instead describe presenting symptoms and outline a treatment approach.4 While patient symptoms and complaints are important and must be considered, diagnosis must be based on patient performance, not exclusively on patient report. Terminology used by patients may be vague. Moreover, consider the false negative rates possible among patients in denial or simply reticent to complain or divulge, as well as the false positives if diagnosis were based on patients’ or parents’ reports, based, for example, on general information they gleaned from the Internet. Let us not forget that diagnosis and labeling conditions allow for clear communication among professionals, suggesting at least in general terms the most appropriate directions for intervention, and that diagnosis is essential to secure coverage by insurers for services rendered.

 

Comorbidity and Intervention

CAPD often presents co-morbidly with other disorders, including language impairment, dyslexia, ADHD, and autism spectrum disorder; however, comorbidity does not imply unity or that one disorder encompasses the other. Differential diagnosis by a multidisciplinary team is required to accurately identify the presence of a disorder and determine intervention. A child diagnosed with CAPD—whether the disorder exists alone or comorbid with another disorder in another domain—should receive deficit-specific auditory interventions. Interventions for general developmental or cognitive disorders typically do not include direct auditory remediation, and if they do, that remediation is offered within the context of other treatments (eg, language, memory, etc) more specific to these other disorders. Understanding and disentangling the effects of cognition and sensory processing are critical for appropriate, effective, and efficient treatment and management of individuals.64

 

Efficacy of Auditory Interventions

Some have criticized auditory training as ineffective because it does not improve language or reading skills7,63,65; however, as noted above, reading and language processing are influenced by many variables, some of which are far removed from the auditory domain.64 The purpose of auditory training is to improve auditory processes, not improve language or reading skills. Auditory training, as a bottom-up strategy, aims to improve sensory processing of individuals with auditory skills deficits2,3,66 with the expectation that such improvement is likely to benefit real-life listening situations. Improvement in areas not directly related to the targeted auditory deficit may occur, but is not the primary goal of auditory training.67

Several recent studies have provided behavioral and electrophysiological evidence that auditory training can improve the auditory processing skills of children with CAPD or auditory-based learning problems.66-73 Tests and procedures are needed to enable early diagnosis of CAPD in children 7 years and younger to maximize the efficacy of intervention. To do so, however, requires research to find measures of sufficient challenge to the CANS that can still be completed by young children without such variability that makes impossible reasonable “cut off” norms. In the meantime, we and others have recommended a number of informal interventions for children who are at risk but have not yet been diagnosed with CAPD.64,74

 

Conclusions

James Jerger, PhD, asserted almost two decades ago that three lines of converging evidence support the reality “of a relatively pure auditory perceptual disorder.” Dr Jerger wrote:

First, there is the accumulation, over the past 30 years, of audiological evidence from children and adults with known lesions of the central auditory system…We can make the not unreasonable inference that when similar symptomatology is observed in children with listening problems, a problem in central auditory processing in the brain is at least suspect. Second, there has been an accumulation, especially over the past decade, of in-depth studies of the specific auditory perceptual deficits of children and adults whose only complaint is an apparent inability to hear well in difficult listening situations. Third, it is becoming increasingly clear that the unique listening problems of elderly persons may, in at least some cases, be related to age-related changes in the central rather than the peripheral auditory system. These three converging lines of evidence provide, I think, more than sufficient basis for accepting the reality of the phenomenon. They demonstrate that, across the entire age range, there are individuals who seem to display symptoms of the auditory perceptual disorder so concisely described by Myklebust.[393-394]75

As cited throughout this commentary, the research base providing the evidence supporting the three lines of converging evidence Jerger noted has grown exponentially since 1998. In more recent years, Jerger recognized (as we also discussed above) that central auditory tests may impose some cognitive load and he encouraged efforts to document auditory processing dysfunction, as well as underlying cognitive mechanisms, that could impact performance on central auditory tests.76

We have also recognized these same interactions,77 but as we cited above, accumulating research substantiates that:

  1. The extent of cognitive influence on central auditory processing is limited, and
  2. Cognition does not drive central auditory processing performance.

As noted by co-author Frank Musiek, who introduced the term “auditory footprint,” the auditory system is extensive: there is a considerable amount of neural substrate involved in processing auditory signals.78 While it is true that the auditory system shares neural substrate with other domains, which is the source of sensory-cognitive interactions, as well as overlapping clinical profiles and co-morbidity, we have clinically useful tools available to determine the primary source(s) of listening difficulties. In addition to efficient auditory behavioral tests, we encourage the use of auditory event-related potentials (AERPs), such as the P300, to assist in clarifying the interplay among auditory, cognitive, and linguistic processes. Certainly, the CANS of individuals who successfully perform the behavioral task and produce repeatable AERPs for a given auditory task must present high auditory integrity, reflecting both the integrity of the neural substrate underlying the behavioral task as well as the neural substrate of the pathways responsible for generating the AERP.77 Consistent with Jerger and Martin’s recommendation,76 we have offered in this commentary (and elsewhere as cited above) clinically useful and effective approaches to disentangle these interactions.

 

References

  1. Filippini R, Weihing J, Chermak GD, Musiek FE. Current issues in the diagnosis and treatment of central auditory processing disorder in children. In: Geffner D & Swain D, eds. Auditory Processing Disorders: Assessment, Management, and Treatment. 3rd ed. San Diego: Singular Publishing Group. In press.
  2. American Academy of Audiology (AAA). Guidelines for the Diagnosis, Treatment, and Management of Children and Adults with Central Auditory Processing Disorder. Available at: http://www.audiology.org/resources/documentlibrary/Documents/CAPD%20Guidelines%208-2010.pdf 2010.
  3. American Speech-Language-Hearing Association. (Central) Auditory Processing Disorders [Technical Report]. 2005. Available from www.asha.org/policy.
  4. Beck D, Clarke J, Moore D. Contemporary issues in auditory processing disorders: 2016. Hearing Review. 2016;23(4):22-27. Available at: http://www.hearingreview.com/2016/03/contemporary-issues-auditory-processing-disorders-2016
  5. DeBonis D. It is time to rethink central auditory processing disorder protocols for school-aged children. Am J Audiol. 2015;24(6):124-136.
  6. de Wit E, Visser-Bochane MI, Steenbergen B, van Dijk P, van der Schans CP, Luinge MR.   Characteristics of auditory processing disorders: A systematic review. J Sp Lang Hear Res. 2016;59(2):384-413.
  7. Fey ME, Richard GJ, Geffner D, Kamhi AG, Medwetsky L, Paul D, Schooling T. Auditory processing disorder and auditory/language interventions: An evidence-based systematic review. Lang Sp Hear Services in Schools. 2010;42(3):246-264.
  8. Ahmmed AU, Ahmmed AA. Setting appropriate pass or fail cut-off criteria for tests to reflect real life listening difficulties in children with suspected auditory processing disorder. Int J Ped Otorhinolaryngol. 2016;84:166-173.
  9. Moore M. Ferguson M, Edmonson-Jones A. Ratib S, Riley A. Nature of auditory processing disorder in children. 2010;126(2):e382-390.
  10. Ferguson MA, Hall RL, Riley A, Moore DR. Communication, listening, cognitive and speech perception skills in children with auditory processing disorder (APD) or Specific Language Impairment (SLI). J Sp Lang Hear Res. 2011;54(1):211-227.
  11. Brenneman L, Cash E, Chermak GD, Guenette L, Masters G, Musiek FE, Brown M, Ceruti J, Fitzegerald K, Geissler K, Gonzalez J, Weihing J. The relationship between pediatric central auditory processing disorder (CAPD) and other childhood disorders. J Am Acad Audiol. In press.
  12. British Society of Audiology (BSA). Position Statement: Auditory Processing Disorder (ADP). 2011: 1-9. Available at: http://www.thebsa.org.uk/images/stories/docs/BSA_APD_PositionPaper_31March11_Final.pdf
  13. US 9th Circuit Court of Appeals. M., a minor, by and through his parents, E.M. and E.M v. Pajaro Valley Unified School District. No. 12-15743. August 2, 2012. Available at: https://www.justice.gov/sites/default/files/crt/legacy/2012/08/06/empajarobrief.pdf
  14. Chermak GD, Bellis TJ, Musiek FE. Neurobiology, cognitive science, and intervention. In: Chermak GD, Musiek FE, eds. Handbook of Central Auditory Processing Disorder: Vol 2. Comprehensive Intervention.  2nd ed. San Diego: Plural Publishing;2014:13-16.
  15. Chermak GD, Tucker E, Seikel JA. Behavioral characteristics of auditory processing disorders and attention deficit hyperactivity disorder predominantly inattentive type.  J Am Acad Audiol. 2002;13:332-338.
  16. Geffner D. Central auditory processing disorders: Definition, description, and behaviors. In: Geffner D & Ross-Swain D, eds. Auditory Processing Disorders. 2nd ed. San Diego: Plural Publishing;2013:59-89.
  17. Musiek FE, Chermak GD. Handbook of Central Auditory Processing Disorder: Vol 1. Auditory Neuroscience and Diagnosis. 2nd ed. San Diego: Plural Publishing;2014.
  18. Rosen S, Cohen M, Vanniasegaram I. Auditory and cognitive abilities of children suspected of auditory processing disorder (APD). Int J Pediatric Otorhinolaryngol. 2010;74(6):594-600.
  19. Sharma M, Purdy SC, Kelly A. Comorbidity of auditory processing, language, and reading disorders. J Sp Lang Hear Res. 2009;52(3):706-722.
  20. Hendler T, Squires N, Emmerich D. Psychophysical measures of central auditory dysfunction in multiple sclerosis: Neurophysiological and neuroanatomical correlates. Ear Hear. 1990;11:403-416.
  21. Matas C, Matas S, Oliveira C, Gonasalves I. Auditory evoked potentials and multiple sclerosis. Arq Neuropsiquiatr. 2010;68(4):528-534.
  22. Valadbeigi A, Weisi F, Rohbakhsh N,  Rezaei M, Heidari A, Rasa A. Central auditory processing and word discrimination in patients with multiple sclerosis. Euro Arch Otorhinolaryngol. 2014;271(11):2891-2896.
  23. Bamiou D-E, Musiek FE, Stow I, Stevens J, Cipolotti L, Brown MM, Luxon LM. Auditory temporal processing deficits in patients with insular stroke. 2006;67(4):614-619.
  24. Bamiou D-E, Werring D, Cox K, Stevens J, Musiek FE, Brown M, Luxon LM. Patient-reported auditory functions after stroke of the central auditory pathway. 2012;43, 1285-1289.
  25. Gates G, Anderson M, McCurry S, Feeney P, Larson E. Central auditory dysfunction as a harbinger of Alzheimer dementia. Arch Otolaryngol Nead Neck Surg. 2011;137(4):390-395.
  26. Pienkowski M, Munguia R, Eggermont JJ. Effects of passive, moderate-level sound exposure on the mature auditory cortex: spectral edges, spectrotemporal density, and real-world noise. Hear Res. 2013;296:121-30.
  27. Fuente A, McPherson B, Hickson L. Central auditory dysfunction associated with exposure to a mixture of solvents. Intl J Audiol. 2011 ;50:857-865.
  28. Musiek FE, Gollegly K, Ross M. Profiles of types of auditory processing disorders in children with learning disabilities. J Childhood Commn Dis. 1985;9:43-63.
  29. Bamiou D-E, Musiek, Luxon LM.  Aetiology and clinical presentations of auditory processing disorders. Arch Disease in Childhood. 2001;85:361-365.
  30. Chermak GD, Musiek FE. Neurological substrate of central auditory processing deficits in children. Current Pediatric Reviews. 2011;7(3):241-251.
  31. Blaettner U, Scherg M, Von Cramon D. Diagnosis of unilateral telencephalic hearing disorders. Evaluation of a simple psychoacoustic pattern discrimination test. 1989;112(1):177-195.
  32. Musiek F, Baran J, Pinheiro M. Duration pattern recognition in normal subjects and patients with cerebral and cochlear lesions. 1990;29(6):304-313.
  33. Musiek F, Baran J, Pinheiro M. P300 Results in patients with lesions of the auditory areas of the cerebrum. J Am Acad Audiol. 1992;3(1):5-15.
  34. Boscariol, M., Casali, R., Amaral, M., Lunardi, L., Matas, C., Collela-Santos, M., & Guerreiro M. Language and central temporal auditory processing in childhood epilepsies. Epilepsy Behavior. 2015;53:180-183.
  35. Boscariol M, Garcia V, Guimarãesa C, Hage S. Montenegro M, Cendes F, Guerreiro M. Auditory processing disorders in twins with perisylvian polymicrogyria. Arq Neuropsiquiatr. 2009;67(2-B):499-501.
  36. Boscariol M, Garcia V,  Guimarãesa C,  Montenegroa M,  Hage S,  Cendes F, Guerreiro M. Auditory processing disorder in perisylvian syndrome. Brain & Development. 2010;32(4):299-304.
  37. Boscariol M, Guimarães CA, Hage, S, Cendes F. Guerreiro M. Temporal auditory processing: correlation with developmental dyslexia and cortical malformation. Pro Fono. 2010;22(4):537-542.
  38. Boscariol M, Guimarães C, Hage S, Garcia V, Schmutzler K, Cendes F, Guerreiro M. Auditory processing disorder in patients with language-learning impairment and correlation with malformation of cortical development. Brain & Development. 2011;33(10), 824-831.
  39. Gyldenkaerne P, Dillon H, Sharma M, Purdy S. Attend to this: The relationship between auditory processing disorders and attention deficits. J Am Acad Audiol. 2014;7:676-687.
  40. Weihing J, Guenette L, Chermak GD, Brown M, Ceruti J, Fitzgerald K, Geissler K, Gonzalez J, Brenneman L, Musiek FE. Characteristics of pediatric performance on a test battery commonly used in the diagnosis of central auditory processing disorder (CAPD). J Am Acad Audiol. 2015;26:652-669.
  41. Grant K. Assessment of functional hearing deficits in active duty service members. Paper presented at: Annual meeting of the American Auditory Society,  Scottsdale, Ariz; March 2017.
  42. Jerger J, Musiek F. Report of the consensus Conference on the Diagnosis of Auditory Processing Disorders in School-Aged Children. J Am Acad Audiol. 2000;11:467-474.
  43. Chermak GD, Bamiou D-E, Iliadou V, Musiek FE. Practical guidelines to minimize language and cognitive confounds in the diagnosis of CAPD: A brief tutorial. Int  J Audiol. 2017;Published online February 28. Available at: http://www.tandfonline.com/doi/abs/10.1080/14992027.2017.1284351?journalCode=iija20
  44. Campbell K, Macdonald M. The effects of attention and conscious state on the detection of gaps in long duration auditory stimuli. Clin Neurophysiol. 2010;122(4):738-747.
  45. Musiek FE, Bellis TJ, Chermak GD. Nonmodularity of the CANS: Implications for (central) auditory processing disorder. Am J Audiol. 2006;14(2):128-138.
  46. Sanes D, Woolley S. A behavioral framework to guide research on central auditory development and plasticity. 2011;72:912-929.
  47. Kileny P, Pacioretti A, Wilson A. Effects of cortical lesions on the middle latency evoked response (MLR). Electroencephalography Clin Neurophysiol. 1987;66(2):108-120.
  48. Knight R, Scabini D, Woods D, Clayworth C. Contributions of temporal-parietal junction to the human auditory P3. Brain Research. 1989;509:102-116.
  49. Polich J, Squire L. P300 from amnesic patients with bilateral hippocampal lesions. Electroencephalography Clinical Neurophysiol. 1993;86, 408-417.
  50. Geissler K, Guenette L, Gonzalez J, Musiek F. A case of severe auditory and short-term memory deficits and related intervention. Paper presented at: Annual convention of the American Academy of Audiology; Anaheim, Calif:April 2013.
  51. Grossmann T, Oberecker R, Koch SP, Friederici AD. The developmental origins of voice processing in the human brain.  2010;65:852-858.
  52. Fitch RH, Miller S, Tallal P. Neurobiology of speech perception.  Annual Review of Neurosci. 1997;20:331-353.
  53. Griffiths TD, Rees A, Green GGR. Disorders of human complex sound processing.  1999;5:365-378.
  54. Shannon RV, Zeng FG, Kamath V, Wygonski J, Ekelid M. Speech recognition with primary temporal cues.  1995;270:303-304.
  55. Zatorre RJ, Belin P. Spectral and temporal processing in human Auditory cortex.  Cerebral Cortex. 2001;11:946-953.
  56. Benavidez D, Fletcher J, Hannay H, et al. Corpus callosum damage and interhemispheric transfer of information following closed head injury in children. 1999;35(3):315-336.
  57. Johnson KL, Nicol TG, Kraus N. Brain stem response to speech: A biological marker of auditory processing. Ear Hear. 2005;26:424-434.
  58. Russo N, Nicol T, Zecker S, Hayes E, Kraus N. Auditory training improves neural timing in the human brainstem. Behav Brain Res. 2005;156:95-103.
  59. Farley Medical Dictionary. “Gold standard.” Available at: http://medical-dictionary.thefreedictionary.com/gold+standard
  60. Musiek FE, Chermak GD, Weihing J, Zappulla M, Nagle S. Diagnostic accuracy of established central auditory processing test batteries in patients with documented brain lesions. J Am Acad Audiol. 2011;22:342-358.
  61. Jerger S, Johnson K, Loiselle L. Pediatric central auditory dysfunction: Comparison of children with a confirmed lesion versus suspected processing disorders. Am J Otol. 1988;9:63-71.
  62. Wilson W, Arnott W. Using different criteria to diagnose (central) auditory processing disorder: How big a difference does it make? J Sp Lang Hear Res. 2013;56:63-70.
  63. Tomlin D, Dillon H, Sharma M, Rance G. The impact of auditory processing and cognitive abilities in children. Ear Hear. 2015;36(5):527-542.
  64. Chermak GD. Central resources training: Cognitive, metacognitive and metalingustic skills and strategies. In: Chermak GD & Musiek FE, eds. Handbook of Central Auditory Processing Disorder: Vol 2. Comprehensive Intervention. 2nd ed. San Diego: Plural Publishing;2014: 243-310.
  65. Debonis D, Moncrieff D. Auditory Processing Disorders: An update for speech-language pathologists. Am J  Speech-Lang Pathol. 2015;17:4-18.
  66. Bellis T, Chermak GD, Weihing J, Musiek F. Efficacy of auditory interventions for central auditory processing disorder: A response to Fey et al. (2011). Lang, Sp, Hear Services in Schools. 2012;43, 381-386.
  67. Weihing J, Chermak GD, Musiek FE. Auditory training for central auditory processing disorder (CAPD). Seminars in Hearing. 2015;36(4):199-215.
  68. Alonso R, Schochat E. The efficacy of formal auditory training in children with central auditory processing disorder: behavioral and electrophysiological evaluation. Braz J Otorhinolaryngol. 2009;75(5):726-32.
  69. Cameron S, Dillon H. Development and evaluation of the LiSN & learn auditory training software for deficit specific remediation of binaural processing deficits in children: Preliminary findings. J Am Acad  Audiol. 2011;22(10):678-696.
  70. Loo JHY, Rosen S, Bamiou D-E. Auditory training effects on the listening skills of children with auditory processing disorder. Ear Hear. 2016;37(1):38-47.
  71. Moncrieff D, Wertz D. Auditory rehabilitation for interaural asymmetry: preliminary evidence of improved dichotic listening performance following intensive training. Int J Audiol. 2008;47(2):84-97.
  72. Sharma M, Purdy SC, Kelly A. A randomized control trial of interventions in school-aged children with auditory processing disorders. Int J Audiol. 2012;51(7):506-518.
  73. Schochat E, Musiek FE, Alonso R, Ogata J. Effect of auditory training on the middle latency response in children with (central) auditory processing disorder. Braz J Med Biological Res. 2010;43(8):777-785.
  74. Musiek FE, Chermak GD, Weihing J. Auditory training. In: Chermak GD & Musiek FE, eds. Handbook of Central Auditory Processing Disorder: Vol 2. Comprehensive Intervention. 2nd ed. San Diego: Plural Publishing; 2014:157-200.
  75. Jerger J. Controversial issues in central auditory processing disorders. Seminars in Hearing. 1998;19(4):393-398.
  76. Jerger J, Martin J. Comments on: Moore D, Rosen S, Bamiou D-E, Campbell N, & Sirimanna T (2013). Evolving concepts of developmental auditory processing disorder (APD): A British Society of Audiology APD Special Interest Group ‘white paper.’ Int J Audiol. 2013;52:11.
  77. Musiek FE, Chermak GD. Perspectives on central auditory processing disorder. Audiology Today. 2016;28(1):24-28.
  78. Poremba A, Saunders RC, Crane AM, Cook M, Sokoloff L, Mishkin M. Functional mapping of the primate auditory system. 2003;299:568-571.

 

CORRESPONDENCE can be addressed to HR or Dr Chermak at: chermak@wsu.edu

 

About the Authors

Gail Chermak, PhD, is Professor of Audiology and Chair of the Department of Speech and Hearing Sciences, Elson S. Floyd College of Medicine, Washington State University Health Sciences Spokane; Frank E. Musiek, PhD, is a Professor in the

Department of Speech, Language, Hearing Sciences at the University of Arizona; and Jeffrey Weihing, PhD, is an Assistant Professor in the School of Medicine at the University of Louisville.

Citation for this article. Chermak GD, Musiek FE, Weihing J. Beyond controversies: The science behind central auditory processing disorder. Hearing Review. 2017;24(5):20-24.

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