Secondary cues to pitch accent in Japanese

Abstract

The perception of Japanese pitch accent was investigated using synthetic speech in which the F0 was artificially removed. While the F0 is said to be the primary cue to pitch accent in Japanese, it is not certain whether acoustic correlates other than F0 exist. The results of previous production studies that examined vowel duration or intensity as a correlate of pitch accent are mixed. The present study attempts to find correlates of pitch accent from the other end, i.e., perception. A native Tokyo Japanese speaker produced 14 disyllabic minimal pairs that differed only in the presence or absence of accent (e.g. /haná/ 'flower' when accented vs. /hana/ 'nose' when unaccented) in a carrier sentence. The utterances were then edited by replacing the F0 with random noise, which is somewhat similar to whispered speech in that there is no voicing. Twenty-two native speakers of Tokyo Japanese identified the words in two kinds of stimuli, the 14 minimal pairs as produced by the speaker and the synthetic speech. The results suggest evidence of pitch accent in synthetic speech. Furthermore, exposure to natural speech seems to improve the listener's ability to identify words in subsequent synthetic speech and vice versa, to varying degrees.