A Study on the Distinctiveness of the Myanmar Four Tones by Means of Fundamental Frequency
MASUKO Yukie
Myanmar is a tone language, in mainland Southeast Asia, of four-tonal distinction. The purpose of this article is to examine the acoustic phonetic characteristics of each tone, as the basis for further examining its related phenomenon, the intonation.
A set of meaningful minimal pair words which have the same initial consonant and rhyme but different tonal patterns were selected. Total of 265 words were pronounced by one native speaker and recorded, and the maximum and the minimum of the fundamental frequency of each tone were measured.
The results are as follows. Though the ranges of the distribution of the four tones are appeared to overlap with one another, each of four tones has its own pattern of distribution. The Level tone (low-level tone called “Teihei-cho” in Japanese terminology) had congested minimum values while the maximum values varied. The Heavy tone (high-level tone called “Kouhei-cho”) had a little difference in the maximum and the minimum value, and the range of distribution of the minimum values was large. The Creaky tone (falling tone called “Kakou-cho”) had a large difference between the maximum and the minimum values. The Stop tone (checked tone called “Sokuon-cho”) had a small difference between the maximum and the minimum values, but the distribution of the maximum values was similar to that of the Creaky tone, and the smaller difference in the Stop tone than the Creaky tone, which is a result of the larger minimum values of the latter. The similarity of the Creaky tone and the Stop tone was therefore observed concerning the fundamental frequency from this experiment.
Since the perception of tone is relevant not only to the fundamental frequency, other aspects should be also taken into consideration. First of all, the duration of the syllable should be examined because the declination in fundamental frequency differs, which is supposed to be relevant to the duration. The fact should be also carefully taken account of that there are some values that are out of the range of congested distribution, because they are still perceived exactly as being realized as the target tone in spite of their value of fundamental frequency. Other factors related to the voice quality such as the state of vocal folds should be taken into consideration.