Hearing Threshold Estimation With Distortion Product Otoacoustic Emission Growth Functions in People With Intellectual Disabilities in an Outreach Setting.

Background: People with intellectual disabilities often have undetected hearing loss.

Methods: In this prospective observational study featuring 110 adults with intellectual disabilities, hearing evaluations based on objective hearing threshold estimation using distortion-product otoacoustic emission growth functions (DPOAEgfs) were performed in a sheltered workshop. Results were compared with thresholds obtained by conventional subjective pure-tone audiometry (cPTA) and the adaptive self-test PTA Multiple-Choice-Auditory-Graphical-Interactive-Check (MAGIC).

Results: The differences between the lowest thresholds obtained by cPTA and MAGIC for the frequencies 1, 2, 4 and 6 kHz (LPTATs) and the estimated distortion-product thresholds (EDPTs) were calculated. Four hundred twenty-seven of 880 (48.5%) pairs of measurements did not differ by any more than 5 dB. With LPTATs as reference criterion, for a favourable four-frequency average over 1.0, 2.0, 4.0 and 6.0 kHz with a cutoff of 20 dB HL, the sensitivity of the EDPTs was 92% and the specificity 62%; a cutoff of 30 dB HL increased the respective values to 98% and 77%.

Conclusions: DPOAEgfs are acceptable for estimating hearing thresholds in individuals with intellectual disability who may have limitations in performing conventional audiometry.