Abstract:
This research aims to study citation tones and tonal coarticulation in Northern Pa-O (N. Pa-O) and Southern Pa-O (S. Pa-O) continuous speech. The data was collected from 20 speakers (10 speakers from each dialect). The test words for citation tones were monosyllabic words. The test words for tones in continuous speech were pairs of test words in sentence frames. The acoustic characteristics of tones were analyzed with 2 methods. F0 was measured at 11 equidistant intervals (every 10%) and converted into semitones. The line graphs were created from semitones with normalized duration. Furthermore, F0 was measured at every 0.01 second and converted into semitones. The semitones were used to generate quadratic trendlines. The results revealed that N. Pa-O and S. Pa-O had 6 tones. The four tones in non-checked syllables were high tone (T1), mid tone (T2), low tone (T3) and falling tone (T4). The two tones in checked syllables were checked high tone (T5) and checked low tone (T6). Certain tones of different dialects were acoustically different in terms of pitch heights, contours and shapes. Regarding tonal coarticulation, there were three types of direction: progressive, regressive, and bidirectional effects. Progressive effects were larger than regressive ones. In Pa-O, only assimilatory tonal coarticuation was found. The research showed that the slopes of tones in continuous speech were greater than citation tones. The results supported the effectiveness of my adaptive method of using polynomial equation to analyze tones (Andruski & Costello, 2004). In addition, the findings reflected gender variation of S. Pa-O tones and tendency of tone sandhi in progress in N. Pa-O.