A child aged 8 years has normal hearing on pure tone audiometry but fails speech-in-noise testing and has academic difficulties. Behavioral audiometry and ABR are normal. The likely diagnosis and primary diagnostic test is:
- A Auditory neuropathy spectrum disorder; diagnosed by absent or abnormal cochlear microphonic on ECochG
- B Auditory processing disorder (APD); diagnosed by central auditory processing battery including dichotic listening and temporal processing tests ✓
- C Functional hearing loss (non-organic); diagnosed by Stenger test and discrepancy between ABR and PTA thresholds
- D Hidden hearing loss; diagnosed by suprathreshold ABR amplitude reduction
Explanation
Auditory Processing Disorder (APD) is characterized by difficulty understanding speech in noise, competing messages, or degraded signals despite normal peripheral hearing thresholds (normal PTA and ABR). It reflects dysfunction in central auditory pathways. Diagnosis requires a formal central auditory processing test battery including dichotic digit and word tests, temporal processing tests (gap detection), binaural interaction tests, and monaural low-redundancy speech tests. Auditory neuropathy shows normal OAE but abnormal ABR. Hidden hearing loss shows normal audiogram but reduced Wave I amplitude on suprathreshold ABR.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
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Written and medically reviewed by the StethoPrep medical team.