Frequency-compression outcomes in listeners with steeply sloping audiograms.

Previous investigation of an experimental, wearable frequency-compression hearing aid revealed improvements in speech perception for a group of listeners with moderately sloping audiograms (Simpson et al, 2005). In the frequency-compression hearing aid, high frequencies (above 1600 Hz) were amplified in addition to being lowered in frequency. Lower frequencies were amplified without frequency shifting. In the present study, an identical frequency-compression scheme was evaluated in a group of seven subjects, all of whom had steeply sloping hearing losses. No significant differences in group mean scores were found between the frequency-compression device and a conventional hearing instrument for understanding speech in quiet. Testing in noise showed improvements for the frequency-compression scheme for only one of the five subjects tested. Subjectively, all but one of the subjects preferred the sound quality of the conventional hearing instruments. In conclusion, the experimental frequency-compression scheme provided only limited benefit to these listeners with steeply sloping hearing losses.