Auditory processing disorders (APD) may be broadly defined as listening difficulties in the absence of hearing loss. It has been reasoned that, because the cochlea functions normally, APD must arise through malfunction of the central nervous system. In several professional society position statements, APD has been considered primarily a problem of sensory, ‘bottom-up’ processing. This is the way the central auditory nervous system (CANS) codes, transforms and interprets neural signals arising from the cochlea and involved in simple (e.g. temporal processing) and complex (e.g. speech perception in noise) auditory tasks. However, increasing evidence over the last 5 years suggests that impaired performance on these same tasks may primarily reflect ‘top-down’ modulation of auditory perception by multimodal cognitive systems including attention, memory and learning. A third perspective is that both sensory and cognitive processes are involved in all aspects of hearing, and that they cannot be segregated. Most current clinical tests for APD involve language-based testing that necessarily involves brain mechanisms beyond the CANS. An important professional issue is whether audiologists can or should test for these higher-level functions. Recent findings suggest that, while most APD is primarily top-down, impaired temporal processing in the cochlea and brainstem may also be involved.
- Convey brief history, presentation, and hypothesized nature of developmental APD.
- Discuss more general interaction between hearing, listening, cognition and language.
- Ask whether APD could result from a newly discovered ‘hidden hearing loss’, a mild form of auditory neuropathy.