title: Acoustic temporal modulation detection and speech perception in cochlear implant listeners.
abstract: The goals of the present study were to measure acoustic temporal modulation transfer functions (TMTFs) in cochlear implant listeners and examine the relationship between modulation detection and speech recognition abilities. The effects of automatic gain control, presentation level and number of channels on modulation detection thresholds (MDTs) were examined using the listeners' clinical sound processor. The general form of the TMTF was low-pass, consistent with previous studies. The operation of automatic gain control had no effect on MDTs when the stimuli were presented at 65 dBA. MDTs were not dependent on the presentation levels (ranging from 50 to 75 dBA) nor on the number of channels. Significant correlations were found between MDTs and speech recognition scores. The rates of decay of the TMTFs were predictive of speech recognition abilities. Spectral-ripple discrimination was evaluated to examine the relationship between temporal and spectral envelope sensitivities. No correlations were found between the two measures, and 56% of the variance in speech recognition was predicted jointly by the two tasks. The present study suggests that temporal modulation detection measured with the sound processor can serve as a useful measure of the ability of clinical sound processing strategies to deliver clinically pertinent temporal information.
authors.affiliation: Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington 98195, USA. jhwon@uw.edu
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Won
authors.forename: Ward R
authors.initials: WR
authors.lastname: Drennan
authors.forename: Kaibao
authors.initials: K
authors.lastname: Nie
authors.forename: Elyse M
authors.initials: EM
authors.lastname: Jameyson
authors.forename: Jay T
authors.initials: JT
authors.lastname: Rubinstein
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001309:Auditory Threshold; D019929:Cochlear Implantation / Q000295:instrumentation*; D003054:Cochlear Implants; D012048:Correction of Hearing Impairment; D003463:Cues; D006801:Humans; D008875:Middle Aged; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D021641:Recognition, Psychology; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception; D013997:Time Factors; D013998:Time Perception