Perception of temporal differences in speech by ‘‘normal-hearing’’ adults: Effects of age and intensity

Publisher Website
Google Scholar
Abstract
Many older people have greater difficulty processing speech at suprathreshold levels than can be explained by standard audiometric configurations. Some of the difficulty may involve the processing of temporal information. Temporal information can signal linguistic distinctions. The voicing distinction, for example, that separates pairs of words such as rapid and rabid can be signaled by temporal information. Longer first vowel and shorter closure characterize rabid, shorter vowel and longer closure characterize rapid. Naturally produced tokens of rabid were low-pass filtered at 3500 Hz and edited to create vowel and (silent) closure duration continua. Pure-tone audiograms and speech recognition scores were used to select the 10 best-hearing subjects among 50 volunteers over age 55. Randomizations of the stimuli were presented for labeling at intensity levels of 60 and 80 dB HL (hearing level) to this group and to 10 normal-hearing volunteers under age 25. Results showed highly significant interactions of age with the temporal factors and with intensity: the older subjects required longer silence durations before reporting rapid, especially for the shorter vowel durations and for the higher intensity level. Age may affect the relative salience of different acoustic cues in speech perception, and the age-related hearing loss may involve deficits in the processing of temporal information, deficits that are not measured by standard audiometry.

This publication has 2 references indexed in Scilit: