Perception of vowel height: Effects of varying F1–F0 difference

Abstract

Perceived vowel height has been reported to vary inversely with the difference (in Bark) between the first formant frequency (F1) and the fundamental frequency (F0) [H. Traunmüller, J. Acoust. Soc. Am. 69, 1465–1475 (1981)]. Syrdal and Gopal [J. Acoust. Soc. Am. 79, 1086–1100 (1986)] observed that naturally produced [+high] and [−high] vowels tend to divide at a critical F1–F0 difference of 3–3.5 Bark, corresponding to the range of the spectral center of gravity effect [L. Chistovich and V. Lublinskaja, Hear. Res. 1, 185–195 (1979)]. In the present study, listeners identified three sets of synthetic vowels varying orthogonally in F1 and F0 and ranging from /i/–/i/, /i/–/eh/, and /eh/–/æ/. For the /i/–/eh/ set, which spanned the [+high]/[−high] distinction, there was a steep identification boundary located at an F1–F0 difference of 3–3.5 Bark. However, for the /eh/–/æ/ and /i/–/i/ sets, which occupied regions where F1–F0 was always greater than or less than 3 Bark, vowel labeling varied more gradually as a function of F1–F0. In fact, for the /i/–/i/ set, F1–F0 was actually a poorer predictor of identification performance than F1 alone. [Work supported by NIDCD.]