ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

4aSC1. Vowel formant discrimination.

Diane Kewley-Port

Dept. of Speech and Hearing Sciences, Indiana Univ., Bloomington, IN 47405

This series of experiments examines the relation between the basic capabilities of the peripheral auditory system to process speech and the classification of speech at more central levels. Psychophysical techniques have been applied to determine listeners' abilities to detect, discriminate, and identify speech sounds. The current series of experiments established that thresholds for the discrimination of vowel formants are constant in the F1 region with a value of F=14 Hz and in the F2 region increase linearly with increasing frequency. This presentation describes three directions of our recent research. First, the effects of various stimulus parameters, including fundamental frequency and consonantal context, on thresholds were explored. Second, excitation pattern models have been shown to account for the significant effects of vowel formant frequency and fundamental frequency on F thresholds. Third, an initial experiment compared formant discrimination to vowel identification for listeners with normal hearing and moderate hearing impairment. Results demonstrated that for the impaired listeners, reduced ability to identify vowels was partially predicted by elevated discrimination thresholds in the F2 region. [Work supported by NIDCD.]