Sluijter A M, van Heuven V J
Holland Institute of Generative Linguistics, Phonetics Laboratory, Leiden University, The Netherlands.
J Acoust Soc Am. 1996 Oct;100(4 Pt 1):2471-85. doi: 10.1121/1.417955.
Although intensity has been reported as a reliable acoustical correlate of stress, it is generally considered a weak cue in the perception of linguistic stress. In natural speech stressed syllables are produced with more vocal effort. It is known that, if a speaker produces more vocal effort, higher frequencies increase more than lower frequencies. In this study, the effects of lexical stress on intensity are examined in the abstraction from the confounding accent variation. A production study was carried out in which ten speakers produced Dutch lexical and reiterant disyllabic minimal stress pairs spoken with and without an accent in a fixed carrier sentence. Duration, overall intensity, formant frequencies, and spectral levels in four contiguous frequency bands were measured. Results revealed that intensity differences as a function of stress are mainly located above 0.5 kHz, i.e., a change in spectral balance emphasizing higher frequencies for stressed vowels. Furthermore, we showed that the intensity differences in the higher regions are caused by an increase in physiological effort rather than by shifting formant frequencies due to stress. The potential of each acoustic correlate of stress to differentiate between initial- and final-stressed words was examined by linear discriminant analysis. Duration proved the most reliable correlate of stress. Overall intensity and vowel quality are the poorest cues. Spectral balance, however, turned out to be a reliable cue, close in strength to duration.
尽管强度已被报道为压力的可靠声学关联指标，但在语言重音感知中，它通常被认为是一个微弱的线索。在自然言语中，重读音节的发音需要更多的发声努力。众所周知，如果说话者发声努力增加，高频的增加幅度会大于低频。在本研究中，在排除混淆的口音变化的情况下，考察了词汇重音对强度的影响。进行了一项产出研究，其中10名说话者在一个固定的载体句子中，分别以有口音和无口音的方式产出荷兰语词汇和重复的双音节最小重音对。测量了持续时间、总体强度、共振峰频率以及四个相邻频带的频谱水平。结果表明，作为重音函数的强度差异主要位于0.5kHz以上，即频谱平衡的变化强调了重读音节元音的高频部分。此外，我们还表明，较高区域的强度差异是由生理努力的增加引起的，而不是由于重音导致共振峰频率的偏移。通过线性判别分析考察了压力的每个声学关联指标区分词首重音和词尾重音单词的潜力。持续时间被证明是最可靠的重音关联指标。总体强度和元音质量是最不明显的线索。然而，频谱平衡结果证明是一个可靠的线索，其强度与持续时间相近。
