Auditory processing disorder (APD) in children: A marker of neurodevelopmental syndrome

Abstract

Currently, there are two major hypotheses concerning the nature of developmental APD. One is conventional, that APD results from impaired ‘bottom-up’ processing of sounds. However, while a conventional view suggests the problem with APD lies in the central auditory nervous system (CANS), we propose that the problem may lie more peripherally, possibly in the ear. Alternatively, processing problems expressed in the ear, hindbrain or auditory cortex could reflect the second hypothesis, ‘top-down’ influences from cortical cognitive processing centers that may exert their influence on the auditory cortex, and be conveyed to lower targets via CANS efferent pathways. A variant of this hypothesis is that the problem may be entirely cognitive, primarily affecting language processing, attention or memory and exerting a non-specific (e.g. supramodal) effect on perception. Whichever of these hypotheses turns out to be correct, we propose that the very high co-occurrence of APD with a wide variety of other auditory- and/or language-based learning disorders may reflect a more general ‘neurodevelopmental syndrome’ (NDS). NDS is conceptualized as a supramodal communication disorder that captures a broad range of currently separate markers (e.g. language, literacy, attention and behavior problems) across age. Data are presented from a large pediatric audiology service to show the extensive co-occurrence between APD and other neurodevelopmental disorders.

Key words::

• listening difficulty
• learning disorder
• cognitive hearing
• auditory perception

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Notes

¹Based on clinical data from over 1000 children referred for APD evaluation at two major hospitals in Ohio, Cincinnati Children's (LLH) and Nationwide Children's Hospital, Columbus (courtesy of Gail Whitelaw).

²Except in the case of tinnitus, which will not be dealt with here. The interested reader is referred to Noreña and Farley (7) for a recent review of tinnitus.

³The BSA special interest group on APD proposed (4,6) that APD be subdivided into Developmental, Acquired and Secondary APD. Developmental APD was defined as ‘Cases presenting in childhood with normal audiometry and no other known aetiology or potential risk factor’.