ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01
4pSC1. The relation between identification and discrimination of vowels by
young normal-hearing and elderly hearing-impaired listeners.
Maureen P. Coughlin
Diane Kewley-Port
Larry E. Humes
Dept. of Speech and Hearing Sciences, Indiana Univ., Bloomington, IN 47405
Four young normal-hearing (YNH) and four elderly hearing-impaired subjects
(EHI) with moderate sloping sensori-neural hearing losses participated in
vowel-identification and formant-discrimination tasks. To examine the
relationship between vowel-identification and formant-discrimination abilities
in conditions differing in audibility, signals were presented at two levels (70
and 95 dB SPL). Four mid-vowels (/I/, /e/, /(cursive beta)/, and /(ae
ligature)/) were chosen as the target signals for both tasks. Identification
performance for the YNH subjects was near ceiling performance. The EHI subjects
averaged 80% for the 95 dB and 69% for the 70 dB SPL presentation level,
although individual subject variability was high. Equivalent discrimination
performance in the F1 region ((Delta)F threshold approximately 30 Hz) was
observed for all four vowels, between groups and across levels. In the F2 region
the EHI subjects' thresholds were elevated compared to the YNH subjects at both
levels, even when the formants appeared to be fully audible (at 95 dB SPL).
Correlational analyses suggested that vowel identification was partially
predicted by reduced ability to discriminate spectral differences in the F2
region (at higher frequencies) as well as the subjects' hearing loss. [Work
supported by NIH and NIA.]