Speech recognition in noise for cochlear implant listeners: benefits of residual acoustic hearing.
The purpose of this study was to explore the potential advantages, both theoretical and applied, of preserving low-frequency acoustic hearing in cochlear implant patients. Several hypotheses are presented that predict that residual low-frequency acoustic hearing along with electric stimulation for high frequencies will provide an advantage over traditional long-electrode cochlear implants for the recognition of speech in competing backgrounds. A simulation experiment in normal-hearing subjects demonstrated a clear advantage for preserving low-frequency residual acoustic hearing for speech recognition in a background of other talkers, but not in steady noise. Three subjects with an implanted "short-electrode" cochlear implant and preserved low-frequency acoustic hearing were also tested on speech recognition in the same competing backgrounds and compared to a larger group of traditional cochlear implant users. Each of the three short-electrode subjects performed better than any of the traditional long-electrode implant subjects for speech recognition in a background of other talkers, but not in steady noise, in general agreement with the simulation studies. When compared to a subgroup of traditional implant users matched according to speech recognition ability in quiet, the short-electrode patients showed a 9-dB advantage in the multitalker background. These experiments provide strong preliminary support for retaining residual low-frequency acoustic hearing in cochlear implant patients. The results are consistent with the idea that better perception of voice pitch, which can aid in separating voices in a background of other talkers, was responsible for this advantage.
Turner
Christopher W
CW
Dept. of Speech Pathology and Audiology, Dept. of Otolaryngology Head and Neck Surgery, University of Iowa, Iowa City, Iowa 52242, USA.
Gantz
Bruce J
BJ
Vidal
Corina
C
Behrens
Amy
A
Henry
Belinda A
BA
D000328:Adult; D000704:Analysis of Variance; D003054:Cochlear Implants; D005260:Female; D034381:Hearing Loss / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D009622:Noise / Q000009:adverse effects*; D013067:Speech Perception / Q000502:physiology*