title: Clear speech perception in acoustic and electric hearing.
abstract: When instructed to speak clearly for people with hearing loss, a talker can effectively enhance the intelligibility of his/her speech by producing "clear" speech. We analyzed global acoustic properties of clear and conversational speech from two talkers and measured their speech intelligibility over a wide range of signal-to-noise ratios in acoustic and electric hearing. Consistent with previous studies, we found that clear speech had a slower overall rate, higher temporal amplitude modulations, and also produced higher intelligibility than conversational speech. To delineate the role of temporal amplitude modulations in clear speech, we extracted the temporal envelope from a number of frequency bands and replaced speech fine-structure with noise fine-structure to simulate cochlear implants. Although both simulated and actual cochlear-implant listeners required higher signal-to-noise ratios to achieve normal performance, a 3-4 dB difference in speech reception threshold was preserved between clear and conversational speech for all experimental conditions. These results suggest that while temporal fine structure is important for speech recognition in noise in general, the temporal envelope carries acoustic cues that contribute to the clear speech intelligibility advantage.
authors.affiliation: Hearing and Speech Research Laboratory, Department of Biomedical Engineering, University of California, Irvine 92697, USA. sliu@uci.edu
authors.forename: Sheng
authors.initials: S
authors.lastname: Liu
authors.forename: Elsa
authors.initials: E
authors.lastname: Del Rio
authors.forename: Ann R
authors.initials: AR
authors.lastname: Bradlow
authors.forename: Fan-Gang
authors.initials: FG
authors.lastname: Zeng
mesh_terms: D000328:Adult; D000368:Aged; D003054:Cochlear Implants; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008144:Loudness Perception / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects; D012044:Regression Analysis; D013018:Sound Spectrography; D013067:Speech Perception / Q000502:physiology*; D014705:Verbal Behavior