Lack of association between otoacoustic emissions and hearing difficulty in subjects with normal hearing thresholds

Evoked otoacoustic emissions (EOAE) are a sensitive indicator of subtle cochlear damage and hence might explain why some people complain of excessive difficulty understanding speech in a background of noise, despite having normal hearing thresholds. This phenomenon has been termed "Obscure Auditory Dysfunction" (OAD). Recorded EOAE waveforms from a group of 50 OAD patients were compared with those from a group of 50 matched controls. No significant difference could be found between the two groups across a range of objective and subjective descriptors of the EOAEs. Any cochlear component of OAD does not appear to affect the function of the outer hair cells sufficiently to modify EOAEs materially.