The goal of this paper is to examine the functions of durational cues and pitch cues in Japanese long vowels and their role in the organization of prosody.
There are two dimensions in the prosodic organization of speech. One is the quantitative or temporal organization, and the other is the qualitative organization, which involves the accentuation/stress system of the language.
The categories of quantitative dimension of prosody at the prosodic-word level used to classify languages are morasyllable-, and stress-/foot- timed. Isochronous distribution of these units in a language has been challenged for several decades; however, the temporal dimension of speech prosody can be measured in phonetic terms as duration. The categories of qualitative dimension of prosody at the prosodic-word level used to classify languages are pitchaccent, tone, and stress. They are captured as the movement of pitch, or the movement of fundamental frequency (F0) in phonetics.
Temporal and accentual dimensions of prosody are bound together in a complex way; however, they can be analyzed as two distinct phonetic properties: duration and F0. In order to fully understand the prosodic organization of a language, we must investigate how these two phonetic signals interact with each other in natural speech.
Two production experiments were conducted. One involved both duration and pitch. The other involved only duration.
The results from these production experiments show that these two phonetic signals influence each other when native speakers of the Tokyo dialect of Japanese produce phonologically long vowels.