英文摘要 |
This study acoustically analyzed monophthongs and diphthongs in Hakka infantdirected speech (IDS) and adult-directed speech (ADS). Ten mother-infant dyads joined this study. The speech stimuli included eleven commonly-used disyllabic phrases, the first syllables of which were the target words. This study selected three clear tokens from each disyllabic phrase, and used PRAAT to measure the values of the first and second formant of all samples, normalized formant values into Bark values, and used Bark values to draw the vowel space of monophthongs and the trajectories of diphthongs, and to count vowel-related acoustic correlates. The results were stated as follows. First, monophthongs and diphthongs in IDS became longer than those in ADS. Second, as compared with ADS, IDS displayed a downward-moving vowel space, a slightly shrinking vowel space area, and shorter acoustic vowel distances. Third, as compared with ADS, IDS showed longer duration and longer acoustic distances in diphthongs. Fourth, the similar onset-rime percentages in both IDS and ADS are helpful for infants to create the concepts of syllables and cultivate the ability of phonological awareness later. |