Delayed Pitch Fall in Japanese: A Perceptual Experiment 116th ASA Meeting, Honolulu, Hawaii, Nov. 17, 1988 KazueHata Speech Technology Laboratory 3888 State Street, Santa Barbara, CA 93105 Yoko Hasegawa Department of Linguistics, University of California Berkeley, CA 94720 yoko@violet.berkeley.edu 1. Introduction The Tokyo dialect of Japanese is a typical pitch accent language in which accent is real- ized solely by a change in fundamental frequency (F0), not by a change in amplitude or duration such as found in English. Phonologically, the accented syllable in Japanese has a high tone, and the post-accent syllable a low tone. Phonetically, the accentual high tone is realized by a higher F0 value on the accented syllable than on the surrounding syllables (Pierrehumbert and Beckman, 1988). However, this F0 peak frequently occurs on the post-accent syllable, without listeners apparently detecting any change in accent. placement-a phenomenon which is called delayed pitch fall. Investigating this phenomenon, Sugito (1972) discovered that the real acoustic correlate of the Japanese accent is a falling F0 contour of the post-accent syllable, rather than the F0 peak location, i.e. native speakers of Japanese perceive an accent on a syllable when it is followed by a falling F0 contour. Hasegawa and Hata (1988) also investigated the phenomenon using naturally- uttered sentences. Figure 1 shows F0 contours of non-delayed and delayed pitch fall tokens. Both of them are instances of the word /namida/ 'tear (noun)', where an accent as conventionally known falls, and native speakers do hear an accent, on the first syll- able. We found that there is a positive correlation between the steepness of F0 fall and the degree of delay in the delayed pitch fall tokens: a delayed pitch fall tends to be steeper the later it occurs. Table 1 provides the median of rated F0 fall in Hz/ csec by subject. For example, Subject 4 shows 10.0 Hz/ csec for delayed tokens as opposed to 6.5 Hz/csec for non-delayed tokens. The overall tendency is for delayed tokens to show a steeper fall in comparison with non-delayed ones.