Department of Linguistics, Ohio State University, Columbus, Ohio 43210, USA.
J Acoust Soc Am. 2024 Oct 1;156(4):2497-2507. doi: 10.1121/10.0032385.
Vowels vary in their acoustic similarity across regional dialects of American English, such that some vowels are more similar to one another in some dialects than others. Acoustic vowel distance measures typically evaluate vowel similarity at a discrete time point, resulting in distance estimates that may not fully capture vowel similarity in formant trajectory dynamics. In the current study, language and accent distance measures, which evaluate acoustic distances between talkers over time, were applied to the evaluation of vowel category similarity within talkers. These vowel category distances were then compared across dialects, and their utility in capturing predicted patterns of regional dialect variation in American English was examined. Dynamic time warping of mel-frequency cepstral coefficients was used to assess acoustic distance across the frequency spectrum and captured predicted Southern American English vowel similarity. Root-mean-square distance and generalized additive mixed models were used to assess acoustic distance for selected formant trajectories and captured predicted Southern, New England, and Northern American English vowel similarity. Generalized additive mixed models captured the most predicted variation, but, unlike the other measures, do not return a single acoustic distance value. All three measures are potentially useful for understanding variation in vowel category similarity across dialects.
美国英语的各地区方言中，元音在声学相似性方面存在差异，以至于在某些方言中，一些元音彼此之间比其他元音更相似。声学元音距离测量通常在离散时间点评估元音相似性，从而导致的距离估计可能无法完全捕捉到共振峰轨迹动态中的元音相似性。在当前的研究中，评估说话人之间随时间变化的声学距离的语言和口音距离测量被应用于说话人内部的元音类别相似性评估。然后，在不同的方言之间比较这些元音类别距离，并检查它们在捕捉美国英语地区方言变化的预测模式方面的有效性。梅尔频率倒谱系数的动态时间 warping 用于评估频谱上的声学距离，并捕捉到预测的美国南部英语元音相似性。均方根距离和广义加性混合模型用于评估选定的共振峰轨迹的声学距离，并捕捉到预测的美国南部、新英格兰和北部英语元音相似性。广义加性混合模型捕获了最多的预测变化，但与其他度量标准不同，它不返回单个声学距离值。这三种度量标准都可用于理解不同方言之间元音类别相似性的变化。
