title: Temporal-envelope reconstruction for hearing-impaired listeners.
abstract: Recent studies suggest that normal-hearing listeners maintain robust speech intelligibility despite severe degradations of amplitude-modulation (AM) cues, by using temporal-envelope information recovered from broadband frequency-modulation (FM) speech cues at the output of cochlear filters. This study aimed to assess whether cochlear damage affects this capacity to reconstruct temporal-envelope information from FM. This was achieved by measuring the ability of 40 normal-hearing listeners and 41 listeners with mild-to-moderate hearing loss to identify syllables processed to degrade AM cues while leaving FM cues intact within three broad frequency bands spanning the range 65-3,645 Hz. Stimuli were presented at 65 dB SPL for both normal-hearing listeners and hearing-impaired listeners. They were presented as such or amplified using a modified half-gain rule for hearing-impaired listeners. Hearing-impaired listeners showed significantly poorer identification scores than normal-hearing listeners at both presentation levels. However, the deficit shown by hearing-impaired listeners for amplified stimuli was relatively modest. Overall, hearing-impaired data and the results of a simulation study were consistent with a poorer-than-normal ability to reconstruct temporal-envelope information resulting from a broadening of cochlear filters by a factor ranging from 2 to 4. These results suggest that mild-to-moderate cochlear hearing loss has only a modest detrimental effect on peripheral, temporal-envelope reconstruction mechanisms.
authors.affiliation: Equipe Audition (CNRS, Universite Paris Descartes, Ecole normale superieure), Institut d'Etude de la Cognition, Ecole normale superieure, Paris Sciences et Lettres, 29 rue d'Ulm, 75005 Paris, France. lorenzi@ens.fr
authors.forename: Christian
authors.initials: C
authors.lastname: Lorenzi
authors.forename: Nicolas
authors.initials: N
authors.lastname: Wallaert
authors.forename: Dan
authors.initials: D
authors.lastname: Gnansia
authors.forename: Agnès Claire
authors.initials: AC
authors.lastname: Leger
authors.forename: David Timothy
authors.initials: DT
authors.lastname: Ives
authors.forename: André
authors.initials: A
authors.lastname: Chays
authors.forename: Stéphane
authors.initials: S
authors.lastname: Garnier
authors.forename: Yves
authors.initials: Y
authors.lastname: Cazals
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003463:Cues; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult