Aerodynamic and Acoustic Effects of Abrupt Frequency Changes in Excised Larynges
Aerodynamic and Acoustic Effects of Abrupt Frequency Changes in Excised Larynges
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DOI：
10.1044/1092-4388(2008/07-0212
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发表时间：
2009-04-01
影响因子：
2.6
通讯作者：
Scherer, Ronald C.
中科院分区：
文献类型：
--
作者：
Alipour, Fariborz;Finnegan, Eileen M.;Scherer, Ronald C.
目的：研究胸腔由声门突变为假声或由胸腔突变为假声对人体的空气动力学和声学效应。假设声门下压力和流量的持续变化(压力-流量扫描[PFS])可以触发犬喉的模式变化。方法：将10只犬喉安装在一个锥形管上，提供加压、加热和加湿空气。在每次PFS实验中记录声门图信号，在此期间气流逐渐增加，持续时间为20~30次。结果：被动喉PFS过程中，基频(F(O))和振型发生突变，内收和伸长没有变化。声带振动的低频模式被感知地识别为胸腔，具有相对较大的幅度振荡、明显的声带接触、丰富的频谱内容和相对较大的音频信号。高频振荡模式被认为是假声，很少或根本没有声带接触，第一部分占主导地位。对于逐渐的内收变化，F(O)也发生了相对突然的变化，胸音对应于较大的内收，假声对应于较少的内收。
Purpose: To determine the aerodynamic and acoustic effects due to a sudden change from chest to falsetto register or vice versa. It was hypothesized that the continuous change in subglottal pressure and flow rate alone (pressure-flow sweep [PFS]) can trigger a mode change in the canine larynx.Method: Ten canine larynges were each mounted over a tapered tube that supplied pressurized, heated, and humidified air. Glottographic signals were recorded during each PFS experiment, during which airflow was increased in a gradual manner for a period of 20-30 s.Results: Abrupt changes in fundamental frequency (F(O)) and mode of vibration occurred during the PFS in the passive larynx without any change in adduction or elongation. The lower frequency mode of oscillation of the vocal folds, perceptually identified as the chest register, had relatively large amplitude oscillation, significant vocal fold contact, a rich spectral content, and a relatively loud audio signal. The higher frequency mode of oscillation, perceptually identified as falsetto, had little or no vocal fold contact and a dominant first partial. Relatively abrupt F(O) changes also occurred for gradual adduction changes, with the chest register corresponding to greater adduction, falsetto to less adduction.