APD Research Overview

Development of a test battery to diagnose APD

One of the aims of our research at the MRC Institute of Hearing Research is to develop a set of tests that can be used to diagnose auditory processing disorder (APD). Over the last year we have been testing typically developing children, and children with language impairment or suspected APD, aged 6-11 years on a large battery of tests. These include tests of:

  • auditory processing e.g. frequency discrimination, backward masking
  • cognitive function e.g. verbal and non-verbal reasoning, memory, reading
  • speech intelligibility e.g. sentences and nonsense words in noise and quiet
  • binaural interaction e.g. dynamic masking level difference
  • spatial hearing e.g. listening in spatialised noise (LISN-S)
  • visual processing e.g. visual spatial frequency discrimination
  • peripheral function e.g. otoacoustic emissions, contralateral suppression
Screenshot of computer game

Our aim is to identify the most useful tests for purpose and then reduce the tests to give a total test session of one hour. This battery will include tests of auditory processing, speech intelligibility and cognitive function. All the tests will be computer driven and are presented as 'fun to do', child-friendly games (see screenshot, left).

To summarise the main findings of our research to date:

  • Effects of age were seen on many of the auditory processing tests
  • Poor auditory processing in typically developing children was associated with poor verbal reasoning and reduced cochlear function
  • More than half of the children with a language impairment had significantly poorer auditory processing performance scores than typically developing children, even after accounting for effects of non-verbal IQ, auditory processing remained poorer in these children
  • There was no relationship between efferent nerve function and either auditory processing tasks or speech intelligibility
  • Different methods of measuring children's attention during testing have been identified

In November 2006, we invited professionals in Audiology and allied disciplines to field test the proposed test battery and provide feedback. All those who responded were sent a questionnaire in December 2006 asking about their interest in APD.