On the sensitivity of older hearing-impaired individuals to acoustic attributes

Abstract

In previous work, we have run a series of experiments with hearing-impaired adults to examine how age and hearing loss affect sensitivity to changes in apparent auditory source width. In two experiments, the interaural coherence of broadband noises presented over headphones and loudspeakers was varied to induce changes in width; in a third, older participants sketched the width of noise, speech, and musical stimuli in simulated rooms with varying reflection absorption. The results of those experiments showed generally decreasing sensitivities to interaural-coherence-induced changes in width as a function of age and hearing impairment. To examine how these results might influence acoustic design for the aged, a new study considers a more basic task that avoided the auditory-visual transformation implicit in sketching. Participants with normal to moderately impaired hearing will compare simulated utterances in a same/different room-discrimination task. Binaural impulse responses will be generated for open-plan buildings of varying size from the ODEON database with sources and receivers centered in each space, convolved with speech and music tokens and presented over headphones. The differences in the relationship between presbycusis and sensitivity to source width vs. general acoustical attributes will be discussed. [Work supported by the MRC and the CSO.]