One characteristic of Japanese pitch accent is that there is the so-called "flat" accent, which has no fall or nucleus. This type of accent exists not only in Standard Japanese but in many dialects, including Kyoto. But the flat types are different in the Tokyo and Kyoto dialects. In the Tokyo dialect, the first syllable always has a low tone and the second a high tone. In the Kyoto flat type, the first and second syllables have the same high tones. Acoustic measurements were made on 144 di-syllabic Kyoto-accented words with the help of a Honeywell 906 C Visicorder. The results indicate that: (1) there are three vowel pitch levels--high, mid and low, but the mid tone linguistically loses its "raison d'etre" because it appears in the flat type or before a high tone, and it does not have any relationship with the nucleus; and (2) the flat type is acoustically unstable in pitch and amplitude. This instability may be one of the reasons why the historical changes in Japanese accent are more conspicuous in the flat type than in the non-flat types. (Author/KM)