A clinical perspective on cochlear dead regions: intelligibility of speech and subjective hearing aid benefit

Using the threshold equalizing noise (TEN) test, 49 subjects with at least two pure-tone thresholds per ear greater than 50 dB HL and none greater than 80 dB HL were evaluated for the presence or absence of dead regions. The purpose of this study was to (1) assess the prevalence of cochlear dead regions in this clinical population, (2) measure whether listeners with dead regions performed differently than listeners without dead regions on a speech intelligibility in noise test, and (3) determine whether cochlear dead regions are associated with reduced subjective hearing aid performance. The results showed that (1) twenty-nine percent of the subjects tested positive for dead regions, (2) listeners with dead regions had poorer sentence understanding in noise than listeners without dead regions and (3) listeners with dead regions perceived poorer subjective hearing aid performance in listening environments with reverberation or background noise as compared to those without dead regions.