Why are nonperipheral vowels avoided?

At the last meeting it was shown that the perception of nonperipheral vowels was poor compared to the perception of peripheral vowels [J. M. Hombert, J. Acoust. Soc. Am. 63, 1 (1978)]. The present study is aimed at investigating the extent to which vowels with the same height value but with very different front/back values can be confused. Speakers of three Cameroonian languages (Kom, Limbum, Moghamo) were asked to classify 53 synthetic vowel stimuli (F1 was varied between 250 and 750 Hz and F2 between 650 and 2350 Hz) according to their own vowel system. The results show that stimuli with drastically different F2 values can be perceived as the same vowel. These data are consistent with our previous findings: The perceptual salience of stimuli with F2 between 1000 and 1500 Hz is less than for stimuli with F2 below or above these values. These data explain at least partially why peripheral vowels are preferred (more frequent) in the languages of the world. [Work supported by NSF.]