Turner Richard E, Walters Thomas C, Monaghan Jessica J M, Patterson Roy D
Gatsby Computational Neuroscience Unit, Alexandra House, 17 Queen Square, London, United Kingdom.
J Acoust Soc Am. 2009 Apr;125(4):2374-86. doi: 10.1121/1.3079772.
This paper investigates the theoretical basis for estimating vocal-tract length (VTL) from the formant frequencies of vowel sounds. A statistical inference model was developed to characterize the relationship between vowel type and VTL, on the one hand, and formant frequency and vocal cavity size, on the other. The model was applied to two well known developmental studies of formant frequency. The results show that VTL is the major source of variability after vowel type and that the contribution due to other factors like developmental changes in oral-pharyngeal ratio is small relative to the residual measurement noise. The results suggest that speakers adjust the shape of the vocal tract as they grow to maintain a specific pattern of formant frequencies for individual vowels. This formant-pattern hypothesis motivates development of a statistical-inference model for estimating VTL from formant-frequency data. The technique is illustrated using a third developmental study of formant frequencies. The VTLs of the speakers are estimated and used to provide a more accurate description of the complicated relationship between VTL and glottal pulse rate as children mature into adults.
本文研究了根据元音共振峰频率估计声道长度（VTL）的理论基础。一方面，开发了一个统计推断模型来描述元音类型与VTL之间的关系，另一方面，描述共振峰频率与声腔大小之间的关系。该模型应用于两项著名的共振峰频率发育研究。结果表明，VTL是继元音类型之后变异性的主要来源，并且相对于残余测量噪声，诸如口咽比例的发育变化等其他因素的贡献较小。结果表明，说话者在成长过程中会调整声道形状，以保持单个元音的特定共振峰频率模式。这种共振峰模式假说是开发从共振峰频率数据估计VTL的统计推断模型的动机。使用第三项共振峰频率发育研究来说明该技术。估计了说话者的VTL，并用于更准确地描述儿童成长为成年人过程中VTL与声门脉冲率之间的复杂关系。
