Bretl Michelle M, Scherer Ronald C
Department of Surgery, Department of Communication Sciences and Disorders, University of Wisconsin - Madison, Madison, WI.
Department of Communication Sciences and Disorders, Bowling Green State University, Bowling Green, OH.
J Voice. 2025 Jan 7. doi: 10.1016/j.jvoice.2024.12.038.
This study aimed to identify voice instabilities across registration shifts produced by untrained female singers and describe them relative to changes in fundamental frequency, airflow, intensity, inferred adduction, and acoustic spectra.
Multisignal descriptive study.
Five untrained female singers sang up to 30 repetitions of octave scales. They first produced these octave scales "naturally," followed by productions that were either deliberately smooth or deliberately unsteady. With all types of scale productions, participants sang with both /α/ and /i/ vowels, at two different dynamic levels, and across both the upper and lower predetermined register transitions. Recorded scales were categorized into three groups (Smooth, Middle, Unsteady) based on researcher-based perceptual smoothness of the auditory signals. These groups allowed for determination of salient features of unsteadiness based on observations and analyses of the acoustic, airflow, intensity, and electroglottography (EGG) waveforms.
A total of 13 different types of instabilities were observed. The number of instabilities within a single scale ranged from zero to fourteen. Most Smooth scales had zero to three instabilities, most Middle scales had four to six, and most Unsteady scales had six or more instabilities within the scale. More obvious instabilities, such as aphonic segments, were present only in Unsteady scales, while more subtle instabilities, such as those related to EGG signal changes, were common in all scale categories, including Smooth scales.
This study revealed that untrained singers can sing smoothly throughout octave scales, and the primary unsteadiness variable was an aphonic segment and corresponding abrupt and large intensity reduction. Particular instabilities may be related to subtle aspects of register change and vocal control. Some objective measures appear to be more visually and numerically salient than auditorily perceived events relative to unsteadiness in the production of scales.
本研究旨在识别未经训练的女性歌手在音区转换时的嗓音不稳定性，并根据基频、气流、强度、推断的内收和声学频谱的变化对其进行描述。
多信号描述性研究。
五名未经训练的女性歌手演唱多达30次的八度音阶。她们首先“自然地”演唱这些八度音阶，随后是刻意平稳或刻意不平稳的演唱。在所有类型的音阶演唱中，参与者用/α/和/i/元音，在两种不同的动态水平下，以及在上下两个预定的音区转换中进行演唱。根据研究人员对听觉信号的感知平滑度，将录制的音阶分为三组（平稳、中等、不平稳）。这些组有助于根据对声学、气流、强度和电声门图（EGG）波形的观察和分析来确定不稳定性的显著特征。
共观察到13种不同类型的不稳定性。单个音阶内的不稳定性数量从零到十四不等。大多数平稳音阶有零到三种不稳定性，大多数中等音阶有四到六种，大多数不平稳音阶在音阶内有六种或更多不稳定性。更明显的不稳定性，如无声段，仅出现在不平稳音阶中，而更细微的不稳定性，如与EGG信号变化相关的不稳定性，在所有音阶类别中都很常见，包括平稳音阶。
本研究表明，未经训练的歌手可以在整个八度音阶中平稳演唱，主要的不稳定性变量是无声段以及相应的突然和大幅强度降低。特定的不稳定性可能与音区变化和发声控制的细微方面有关。相对于音阶演唱中的不稳定性，一些客观测量在视觉和数值上似乎比听觉感知的事件更显著。
