Aging effects on the ability to use temporal context in speech perception

Elderly and young adults listened to a continuum of stimuli varying in closure duration from “rabid” to “rapid” presented at fast and normal speaking rates, with a carrier phrase and in isolation. Rates for the phrase and word were either consistent or conflicting, to determine the relative influence of extrinsic versus intrinsic temporal cues. In addition, the effect of intensity level was examined for all the above conditions. Hearing sensitivity was within normal limits through the low-pass cutoff frequency (3.15 kHz) for the filtered speech. In contrast to previous findings with isolated words [P. J. Price and H. J. Simon, J. Acoust. Soc. Am. 76, 406–509 (1984)], no significant overall age effects were seen for either the word alone conditions at the higher intensity or for any of the phrase + word conditions. These results suggest that, when hearing sensitivity is controlled, age per se may not explain the increased difficulty that many elderly have in processing fast speech. Follow-up research is planned to determine why these data conflict with previous findings.