PERCEPTION OF VOWEL HEIGHT - THE ROLE OF F-1-F-0 DISTANCE

Perceived vowel height has been reported to vary inversely with the di stance (in Bark) between the first formant frequency (F-1) and the fun damental frequency (F-0) [H. Traunmuller, J. Acoust. Soc. Am. 69, 1465 -1475 (1981)]. Syrdal and Gopal [J. Acoust. Soc. Am. 79, 1086-1100 (19 86)] observed that naturally produced [+high] and [-high] vowels tend to divide at a critical F-1-F-0 distance of 3-3.5 Bark, corresponding to the bandwidth of the ''center of gravity'' effect [L. Chistovich an d V. Lublinskaja, Hear. Res. 1, 185-195 (1979)]. In the present study, listeners identified three sets of synthetic vowels varying orthogona lly in F-1 and F-0 and ranging from /i/-/I/, /I/-/epsilon/, and /epsil on/-/ae/. For the /I/-/epsilon/ set, which corresponds to the [+high]/ [-high] distinction, there was a relatively sharp identification bound ary located at an F-1-F-0 distance of 3-3.5 Bark. However, for the /ep silon/-/ae/ and /i/-/I/ sets, which occupied regions where the F-1-F-0 distance was always greater than or always less than 3 Bark, vowel la beling varied more gradually as a function of F-1-F-0 distance. Also, F-1-F-0 distance was a better predictor of labeling performance than F -1 alone only for the /I/-/epsilon/ set. Possible sources of the F-1-F -0 distance cue for vowel height are discussed.