Hearing difficulties greater than would be expected from pure tone audiometry. The hearing difficulties are worse with speech compared with environmental sounds and are particularly affected by background noise.

It is characterised by normal outer hair cell (OHC) function but impaired neural transmission resulting in disruption of coding of acoustic signals in the auditory system.

• Speech tests (in quiet and noise) worse than expected from audiometry.

• Presence of OHC function as measured with cochlear microphonics (CM) and otoacoustic emissions (OAEs)

• Absence or abnormality of the auditory brainstem response (ABR)

Auditory Processing Disorder

APD is diagnosed on the basis of the following criteria:

1. Normal audiometric thresholds in both ears

2. Abnormal performance in at least two validated auditory processing tests that assess different processes in at least one ear, including in a non-speech test

3. Presence of listening difficulties and/or risk factors associated with APD

4. Normal non-verbal intelligence

5. Good ability to follow test instructions

Neurological

• Brain tumours

• Stroke

• De-myelinating conditions

• Epilepsy

• Prematurity/low birth weight

Higher Order Processing/Language

• Higher order language:

  • Developmental disorders: Language impairment

  • Dyslexia

• Higher order processing

  • ADHD, Autism, Etc

Spatial Processing disorder

• Prolonged childhood history of chronic otitis media, can result in deficits to auditory processing