Evaluation of the effects of nonlinear frequency compression on speech recognition and sound quality for adults with mild to moderate hearing loss.
OBJECTIVE
While potentially improving audibility for listeners with considerable high frequency hearing loss, the effects of implementing nonlinear frequency compression (NFC) for listeners with moderate high frequency hearing loss are unclear. The purpose of this study was to investigate the effects of activating NFC for listeners who are not traditionally considered candidates for this technology.


METHODS
Participants wore study hearing aids with NFC activated for a 3-4 week trial period. After the trial period, they were tested with NFC and with conventional processing on measures of consonant discrimination threshold in quiet, consonant recognition in quiet, sentence recognition in noise, and acceptableness of sound quality of speech and music.


METHODS
Seventeen adult listeners with symmetrical, mild to moderate sensorineural hearing loss participated. Better ear, high frequency pure-tone averages (4, 6, and 8 kHz) were 60 dB HL or better.


RESULTS
Activating NFC resulted in lower (better) thresholds for discrimination of /s/, whose spectral center was 9 kHz. There were no other significant effects of NFC compared to conventional processing.


CONCLUSIONS
These data suggest that the benefits, and detriments, of activating NFC may be limited for this population.
* Deparment of Hearing and Speech Sciences, Vanderbilt University Medical Center , Nashville , USA.
Erin M
EM
Picou
Steven C
SC
Marcrum
Todd A
TA
Ricketts
D000328:Adult; D000368:Aged; D001302:Audiometry, Speech / Q000379:methods; D001307:Auditory Perception / Q000502:physiology; D001309:Auditory Threshold; D012048:Correction of Hearing Impairment / Q000379:methods*; D004867:Equipment Design; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013067:Speech Perception
Nonlinear frequency compression; consonant recognition; sentence recognition; sound quality