普通话变调上声与阳平一样吗——基于严格平行语料的语音声学分析

Is the 3rd Tone Sandhi the Same as the 2nd Tone in Mandarin:An Acoustic Analysis Based on Strictly Parallel Speech Data

目前学界在普通话上声连读后前字变调与阳平调是否存在差异这一问题上仍存在相互矛盾的观点。本文选择仅前字声调不同的词或字构成最小对立对,统计分析严格控制条件下二者是否存在声学差异。结果显示,二者调值、调形、音长都不存在差异。二者音高极值、拐点位置差异不普遍存在于所有条件中,相同条件下男女性别发音人差异表现不完全一致,不能认定二者调值、音高拐点位置有差异。音高升幅、升速,音长(音节、声调)无差异。有无框架句、语法结构、真假词等因素对两种声调的声学表现有相似影响。若将不同条件下的二者进行比较,可能得出变调上声音高更高、拐点更前或相反的不同结果,以往认为二者存在声学差异很可能是由于对语料没有进行严格控制。

The investigation into whether a pitch distinction exists between the 3rd tone sandhi before another 3rd tone and the 2nd tone has been a long-standing focus in Mandarin phonetics.Prior acoustic experiments faced challenges due to significant material variations and typically only regulated the prosody of the list of experimental words,neglecting factors such as grammar in the word pairs or phrases.As a result,different experiments yielded inconsistent outcomes.To address these issues,our study meticulously assembled a set of minimal pairs with three identical grammatical structures:predicate-complement,predicate-object,and attributive,alongside pseudo-words.Additionally,the study controlled for whether the minimal pairs were spoken within a frame sentence.Utilizing a repeated measures method,our research scrutinized the pitch values and contours of the initial syllables under different conditions when only the initial tone differed in T3+T3 or T2+T3 sequences.Specifically,we comprehensively measured the maximum and minimum pitch values,pitch rise magnitude,speed,time span,syllable duration,and tone duration.The findings revealed no significant differences in pitch values,pitch contours,or duration between them.Numerically small variations in pitch extremes and the percentage of duration during pitch rise were not universally present under all conditions.Furthermore,the performance of individuals of different genders under the same conditions displayed inconsistencies,challenging the conclusion of differences in pitch values and time span of pitch rise between them.No significant differences were observed in the magnitude and speed of pitch rise,as well as in both the duration of tone and syllable.Moreover,factors such as speaking within a frame sentence,grammatical structure,and the use of pseudowords impacted both their acoustic performances,with similar influence.Comparisons between the two tones under different conditions may yield diverse results,such as a higher pitch or a shorter time span of pitch rising for the 3rd tone sandhi,challenging the previous notion of acoustic differences.Additionally,we addressed the case of the 3rd tone sandhi in low-vowel syllables,a condition in which previous studies suggested that the 3rd tone sandhi differs more from the 2nd tone.However,in our experiments,the pitch extremes of the 3rd tone sandhi in low-vowel syllables lowered slightly more from the 2nd tone than overall,but the difference between the two was still very small.This outcome not only indicates the absence of substantial pitch differences between the 3rd tone sandhi before another 3rd tone and the 2nd tone but also underscores the necessity of stringent control over non-phonetic factors in the comparative study of tone.