Questioning APD in 2015
DeBonis (2015) reviewed the literature with regard to central auditory processing disorders (CAPD) in children to assess “whether the degree of uncertainty surrounding CAPD warrants a change in current protocols….” Relevant search terms and topics were evaluated through contemporary electronic search tools and published peer-reviewed texts.
With regard to the definition of CAPD, the author reminds us “…the processing of spoken language entails the intertwining of auditory, cognitive, and language mechanisms that are often engaged simultaneously” (Medwetsky, 2011). DeBonis states that dichotic listening tasks are significantly influenced by “attentional resources” and performance differences between ears may be minimized “when memory is controlled” (Martin et al, 2007). McFarland and Cacace (2009) concluded that dichotic measures “are not well suited and, for that matter, are less than optimal for studying disorders of auditory perception.” Anderson and Kraus (2010) report that auditory attention is required to extract meaningful speech sounds from noise, and the extracted information needs to be store in the person’s working memory. Rudner et al (2011) determined the crucial factor with regard to understanding speech in noise was working memory. Ferguson et al (2011) hypothesized that the underlying deficit (in CAPD) is attention, and this becomes increasingly apparent as the acoustic environment becomes more challenging. Kelly (2009) reported that of 49 children diagnosed with CAPD, 82 percent failed a frequency pattern task. Sutcliffe and Bishop (2002) reported that when attention effects were controlled, correlations with CAPD test scores to auditory processing, language, reading, and attention (in 6- and 7-year-olds) vanished. The British Society of Audiology (2011) concluded that CAPD is “closely associated with impaired top-down, cognitive function” and there exists no evidence that CAPD is produced “by a primary, sensory disability.”
DeBonis states that “the reality of CAPD as a diagnostic construct is still far from any scenario that will put an end to the ongoing questioning of both its existence and its value….” He reports that testing of CAPD is substantially influenced by non-auditory factors (memory, attention, language, executive function) and the lack of agreement with respect to performance criteria (to diagnose CAPD) is a real concern, and “the contribution of auditory processing abilities to language, reading, and academic and listening abilities, as assessed by current measures, is not significant.” DeBonis notes that the effectiveness of typical intervention programs to improve communication ability “has not been established.” Likewise, Fey and colleagues (2011) reviewed all peer-reviewed articles (between 1978 and 2008) addressing auditory or language interventions. The authors did not find any “compelling evidence that existing auditory interventions make any significant contributions to auditory, language, or academic outcomes of school-aged children who have been diagnosed with CAPD….”
DeBonis concludes that “routine use of CAPD test protocols cannot be supported…” and he states “it is ironic that the popularity of the construct (CAPD) continues to grow on the unsupported notion that auditory processing deficits cause a range of global language and listening deficits” and, “Research now suggests that auditory processing skills, as measured by routinely used tools, contribute very little to difficulties in reading, spelling, academic achievement, or even listening ability….”
For More Information, References, and Recommendations
British Society of Audiology, 2007. Auditory Processing Disorder Steering Comm Interim Position Statement on APD
Cox LC, McCoy SL, Tun PA, Wingfield A. (2008): Monotic Auditory Processing Disorder Tests in the Older Adult Population. Journal of the American Academy of Audiology 19:293–208.
Dawes P. (2011) The SCAN-A in Testing for Auditory Processing Disorder in a Sample of British Adults. International Journal of Audiology 50:107–111.
DeBonis DA. (2015) It Is Time to ReThink Central Auditory Processing Disorder Protocols for School-Aged Children. American Journal of Audiology 24(6):124-136.
Dillon H, Cameron S, Glyde H, Wilson W, Tomlin D. (2012) An Opinion on the Assessment of People Who May Have an Auditory Processing Disorder. Journal of the American Academy of Audiology 23:97–105.
Ferguson M. (2009) Diagnosing Auditory Processing Disorders. ENTNews, In Audiology Matters. February, 2009.
Ferguson MA, Hall RL, Riley A, Moore DR. (2011) Communication, Listening, Cognitive, and Speech Perception Skills in Children With Auditory Processing Disorder (APD) or Specific Language Impairment (SLI). Journal of Speech, Language and Hearing Research 54(2):211–227.
Kreisman NV, John AB, Kreisman BM, Hall JW, Crandell CC. (2012) Psychosocial Status of Children with Auditory Processing Disorder. Journal of the American Academy of Audiology 23:222-233.
Moore DR. (2006) Auditory Processing Disorder (APD): Definition, Diagnosis, Neural basis and Intervention. Audiological Medicine 4:4-11.
Sharma M, Purdy SC, Kelly AS. (2012) A Randomized Control Trial of Interventions in School-Aged Children with Auditory Processing Disorders. International Journal of Audiology 51:506–518.
Wilson WJ, Arnott W. (2013) Using Different Criteria to Diagnose Central Auditory Processing Disorder – How Big a Difference Does it Make? Journal of Speech, Language and Hearing Research 56:63-70.