Ne. Vaughan et T. Letowski, EFFECTS OF AGE, SPEECH RATE, AND TYPE OF TEST ON TEMPORAL AUDITORY PROCESSING, Journal of speech language and hearing research, 40(5), 1997, pp. 1192-1200
Cognitive slowing that accompanies aging may be reflected in temporal
aspects of auditory processing. The purpose of this study was to inves
tigate the effects of age, type of test, and rate of speech on tempora
l auditory processing. Listeners were divided into three groups: young
(25- to 35-year-olds), middle aged (45- to 55-year-olds), and older (
65- to 75-year-olds). A method of time compression known as Synchroniz
ed Overlap Add (SOLA) was used to increase the rate of speech. This me
thod provides a high-quality speech signal and limits the distortions
that may confound the temporal effects on time-compressed tests of spe
ech intelligibility. Listeners performed four speech understanding tas
ks: sentence repetition, sentence intelligibility rating, connected di
scourse intelligibility rating, and connected discourse comprehension
question and answers at three time-compression rates (60%, 70%, and 80
%). Although the older group performed more poorly on all tests, only
the connected discourse intelligibility rating test was sensitive to a
ge differences among all three groups. This difference did not appear
to increase with rate increases but was present only at the 70% compre
ssion rate. In addition, variability was especially high in the oldest
group of participants.