title: The effect of hearing impairment on localization dominance for single-word stimuli.
abstract: Localization dominance (one of the phenomena of the "precedence effect") was measured in a large number of normal-hearing and hearing-impaired individuals and related to self-reported difficulties in everyday listening. The stimuli (single words) were made-up of a "lead" followed 4 ms later by a equal-level "lag" from a different direction. The stimuli were presented from a circular ring of loudspeakers, either in quiet or in a background of spatially diffuse babble. Listeners were required to identify the loudspeaker from which they heard the sound. Localization dominance was quantified by the weighting factor c [B.G. Shinn-Cunningham et al., J. Acoust. Soc. Am. 93, 2923-2932 (1993)]. The results demonstrated large individual differences: Some listeners showed near-perfect localization dominance (c near 1) but many showed a much reduced effect. Two-thirds (64/93) of the listeners gave a value of c of at least 0.75. There was a significant correlation with hearing loss, such that better hearing listeners showed better localization dominance. One of the items of the self-report questionnaire ("Do you have the impression of sounds being exactly where you would expect them to be?") showed a significant correlation with the experimental results. This suggests that reductions in localization dominance may affect everyday auditory perception.
authors.affiliation: MRC Institute of Hearing Research (Scottish Section), Glasgow Royal Infirmary, Alexandra Parade, Glasgow G31 2ER, United Kingdom. maa@ihr.gla.ac.uk
authors.forename: Michael A
authors.initials: MA
authors.lastname: Akeroyd
authors.forename: Fiona H
authors.initials: FH
authors.lastname: Guy
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001302:Audiometry, Speech; D001309:Auditory Threshold; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D006311:Hearing Disorders / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology*; D012044:Regression Analysis; D013017:Sound Localization; D013065:Speech Intelligibility; D013067:Speech Perception; D013997:Time Factors