Multi-band frequency compression for sensorineural hearing impairment

Abstract

Sensorineural hearing loss is associated with widening of the auditory filters, leading to increased spectral masking and degraded speech perception. Multi-band frequency compression can be used for reducing the effect of spectral masking. The speech spectrum is divided into a number of bands and spectral samples in each of these bands are compressed towards the band center, by a constant compression factor. In the present study, we have investigated the effectiveness of the scheme for different compression factors, in improving the speech perception. Evaluation of the scheme using the modified rhyme test showed maximum improvement in recognition scores for compression factor of 0.6: about 17 % for the normal-hearing subjects under simulated hearing loss, and 6–21 % for the subjects with moderate to severe sensorineural hearing loss.