Speech-cue enhancement for the hearing impaired: amplification of burst/murmur cues for improved perception of final stop voicing.

A further study is reported from a program of research exploring the improvement of speech perception by hearing-impaired persons via enhancement of acoustic features of consonants (10,11). Enhancements were applied to certain acoustic segments of consonants, segments known to be useful in consonant perception by normal-hearing persons but often not for persons with severe/profound hearing losses. The consonants were /k/, /t/, /g/, and /d/ located as the final phoneme in /baeC/ words; the voicing feature difference of /k/ versus /g/ and /t/ versus /d/ was the focus of study. The results showed that stop voicing perception improved to at least 90 percent for 3/4 of the listeners when the voiced murmur segments during /d/ and /g/ and the release bursts of /t/ and /k/ were amplified above their natural levels. The audibility of the enhanced segments generally explained differences between the listeners who showed large versus minimal improvements. One training session for stop voicing perception with the cue-enhanced words seemed sufficient to effect maximum performance improvement.