Fundamental frequency and perceived vowel duration

Abstract

What is the relationship between variations in fundamental frequency and perceived duration? At the last meeting of the Society, Prof. Lehiste presented some data dealing with this question. Basically, she found that when listeners are asked to judge the duration of pairs of vowels of equal duration they typically judge the first member of the pair as longer than the second. However, when the second member of the pair contained some variation in FO, listeners perceived it as longer than the first stimulus. In this paper we present the results of two experiments that bear on the general questions raised by Prof. Lehiste's findings. Subjects were presented with all possible pairs of synthetic vowels which varied in duration (160, 200, 240 msec) and fundamental frequency (falling: 200–90 Hz; level: 145 Hz; or rising: 90–200 Hz). They were asked to judge which vowel was longer. The results showed that, in general, vowels containing either a rise or a fall in fundamental frequency were perceived as longer than the corresponding vowels with level fundamentals. These findings were true regardless of the order of presentation of the pair of vowels. The results will be discussed in terms of the interaction between segmental and suprasegmental cues in speech perception. [Research supported by NINCDS Grants NS-12179-01 and NS-07040-01.]