Effect of spectral distance on vowel height perception

Abstract

Perceived vowel height has been reported to vary inversely with the distance (in Bark) between the first formant frequency (F1) and the fundamental frequency (F0) [H. Traunmueller, J. Acoust. Soc. Am. 69, 1465–1475 (1981)]. However, in a study using back vowels, Fahey et al. [J. Acoust. Soc. Am. 99, 2350–2357 (1996)] found that phonetic quality was not only determined by the F1−F0 distance, but also by the tonotopic distances between any adjacent spectral peaks (e.g., F3−F2, F2−F1, and F1−F0), with greater weight accorded to smaller distances. The present study further tested this possibility by using front vowels. Listeners identified three sets of synthetic vowels varying orthogonally in F1 and F0 and ranging from /i/–/ɪ/, /ɪ/–/ε/, or /ε/–/æ/. The results allowed this possibility to be rejected. Furthermore, they supported the study of Hoemeke and Diehl [J. Acoust. Soc. Am. 96, 661–674 (1994)] that F1−F0 was the best predictor of perceived vowel height for the phonological distinction [+/−high] (i.e., the /ɪ/–/ε/ distinction), while F1 alone was the best predictor for the two other vowel set distinctions. [Work supported by NIDCD.]