Groll Matti D, Peterson Sean D, Zañartu Matías, Vojtech Jennifer M, Stepp Cara E
Department of Biomedical Engineering, Boston University, Boston, Massachusetts; Department of Speech, Language, and Hearing Sciences, Boston University, Boston, Massachusetts.
Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario, Canada.
J Voice. 2025 Mar;39(2):345-352. doi: 10.1016/j.jvoice.2022.09.016. Epub 2022 Nov 3.
Relative fundamental frequency (RFF) is an acoustic measure of changes in fundamental frequency during voicing transitions. The physiological mechanisms underlying RFF remain unclear. Recent modeling suggests that changes in RFF during voicing offset are due to decreases in overall system stiffness as a direct result of the cessation of vocal fold collision. To evaluate this finding empirically, here we examined whether variable timing between the end of vocal fold collision and the final voicing cycle used to calculate RFF explained the variability in RFF across individual voicing offset utterances.
RFF during voicing offset was calculated from /ifi/ utterances produced by 35 participants under endoscopy, with and without vocal effort. RFF was calculated via two methods, in which utterances were aligned by (1) the end of vocal fold collision, or (2) the end of voicing. Analyses of variance were used to determine the effects of vocal effort and RFF method on the mean and standard deviation of RFF.
Aligning by vocal fold collision resulted in statistically significantly lower standard deviations. RFF means were statistically higher using the collision method; however, the degree of vocal effort was statistically significant regardless of the method.
These results provide empirical evidence to support that decreases in RFF during voicing offset are a result of decreases in system stiffness due to termination of vocal fold collision.
相对基频（RFF）是发声转换过程中基频变化的一种声学测量指标。RFF背后的生理机制尚不清楚。最近的模型表明，发声结束时RFF的变化是由于声带碰撞停止导致整个系统刚度降低的直接结果。为了通过实验评估这一发现，我们在此研究了声带碰撞结束与用于计算RFF的最终发声周期之间的可变时间是否解释了个体发声结束话语中RFF的变异性。
发声结束时的RFF由35名参与者在内镜检查下发出的/ifi/话语计算得出，分为有声努力和无声努力两种情况。RFF通过两种方法计算，其中话语通过（1）声带碰撞结束或（2）发声结束进行对齐。方差分析用于确定发声努力和RFF方法对RFF均值和标准差的影响。
通过声带碰撞对齐导致标准差在统计学上显著降低。使用碰撞方法时RFF均值在统计学上更高；然而，无论采用何种方法，发声努力程度在统计学上均具有显著性。
这些结果提供了实证证据，支持发声结束时RFF的降低是由于声带碰撞终止导致系统刚度降低的结果。
