title: The perception of apparent auditory source width in hearing-impaired adults.
abstract: In a previous study [Whitmer, Seeber and Akeroyd, J. Acoust. Soc. Am. 132, 369-379 (2012)], it was demonstrated that older hearing-impaired (HI) listeners produced visual sketches of headphone-presented noises that were insensitive to changes in interaural coherence. The current study further explores this insensitivity by comparing (a) binaural temporal fine-structure (TFS) resolution and (b) sound localization precision to (c) auditory source width judgments. Thirty-five participants aged 26-81 years with normal to moderately impaired hearing (a) discriminated interaurally phase-shifted tones from diotic tones presented over headphones, (b) located 500-ms speech-spectrum filtered click trains presented over loudspeakers between ±30° in quiet, and (c) sketched the perceived width of low-pass, high-pass, and speech-spectrum noise stimuli presented over loudspeakers from 0° and simultaneously from ±45° at attenuations of 0-20 dB to generate partially coherent stimuli. The results showed a decreasing sensitivity to width with age and impairment which was related to binaural TFS threshold: the worse one's threshold-which was correlated with age-the less the perceived width increased with decreasing interaural coherence. These results suggest that senescent changes to the auditory system do not necessarily lead to perceptions of broader, more diffuse sound images based on interaural coherence.
authors.affiliation: MRC/CSO Institute of Hearing Research-Scottish Section, Glasgow Royal Infirmary, Glasgow, G31 2ER, United Kingdom.
authors.forename: William M
authors.initials: WM
authors.lastname: Whitmer
authors.affiliation: MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD, United Kingdom.
authors.forename: Bernhard U
authors.initials: BU
authors.lastname: Seeber
authors.affiliation: MRC/CSO Institute of Hearing Research-Scottish Section, Glasgow Royal Infirmary, Glasgow, G31 2ER, United Kingdom.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Akeroyd
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D007600:Judgment; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009038:Motion; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology*; D011571:Psychoacoustics; D013016:Sound; D013017:Sound Localization; D013018:Sound Spectrography; D013997:Time Factors