The role of continuous low-frequency harmonicity cues for interrupted speech perception in bimodal hearing.
Low-frequency acoustic cues have been shown to enhance speech perception by cochlear-implant users, particularly when target speech occurs in a competing background. The present study examined the extent to which a continuous representation of low-frequency harmonicity cues contributes to bimodal benefit in simulated bimodal listeners. Experiment 1 examined the benefit of restoring a continuous temporal envelope to the low-frequency ear while the vocoder ear received a temporally interrupted stimulus. Experiment 2 examined the effect of providing continuous harmonicity cues in the low-frequency ear as compared to restoring a continuous temporal envelope in the vocoder ear. Findings indicate that bimodal benefit for temporally interrupted speech increases when continuity is restored to either or both ears. The primary benefit appears to stem from the continuous temporal envelope in the low-frequency region providing additional phonetic cues related to manner and F1 frequency; a secondary contribution is provided by low-frequency harmonicity cues when a continuous representation of the temporal envelope is present in the low-frequency, or both ears. The continuous temporal envelope and harmonicity cues of low-frequency speech are thought to support bimodal benefit by facilitating identification of word and syllable boundaries, and by restoring partial phonetic cues that occur during gaps in the temporally interrupted stimulus.
Department of Communication Sciences and Disorders, University of South Florida, PCD 1017, 4202 East Fowler Avenue, Tampa, Florida 33620, USA.
Soo Hee
SH
Oh
Department of Communication Sciences and Disorders, University of South Florida, PCD 1017, 4202 East Fowler Avenue, Tampa, Florida 33620, USA.
Gail S
GS
Donaldson
Department of Communication Sciences and Disorders, Northeastern University, 226 Forsyth Building, 360 Huntington Avenue, Boston, Massachusetts 02115, USA.
Ying-Yee
YY
Kong
D000161:Acoustic Stimulation; D000162:Acoustics; D000293:Adolescent; D000328:Adult; D001302:Audiometry, Speech; D019929:Cochlear Implantation / Q000295:instrumentation; D003054:Cochlear Implants; D003463:Cues; D004558:Electric Stimulation; D006801:Humans; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D010507:Periodicity; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D010700:Phonetics; D013018:Sound Spectrography; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013067:Speech Perception; D013997:Time Factors; D055815:Young Adult