Lee Shao-Hsuan, Lee Guo-She
Department of Audiology and Speech Language Pathology, Mackay Medical College, New Taipei City, and Department of Speech Language Pathology and Audiology, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan.
School of Medicine, College of Medicine, Yangming Campus, National Yang Ming Chiao Tung University, and Department of Otorhinolaryngology, Taipei City Hospital Renai Branch, Taipei, Taiwan.
J Voice. 2025 Jan;39(1):25-36. doi: 10.1016/j.jvoice.2022.07.026. Epub 2022 Aug 30.
To investigate whether voice focus adjustments can alter the audio-vocal feedback and consequently modulate speech/voice motor control. Speaking with a forward-focused voice was expected to enhance audio-vocal feedback and thus decrease the variability of vocal fundamental frequency (F0).
Twenty-two healthy, untrained adults (10 males and 12 females) were requested to sustain vowel /a/ with their natural focus and a forward focus and to naturally read the nasal, oral, and mixed oral-nasal sentences in normal noise-masked auditory conditions. Meanwhile, a miniature accelerometer was externally attached on the noise to detect the nasal vibrations during vocalization. Audio recordings were made and analyzed using the long-term average spectrum (LTAS) and power spectral analysis of F0.
Compared with naturally-focused vowel production and oral sentences, forward-focused vowel productions and nasal sentences both showed significant increases in nasal accelerometric amplitude and the spectral power within the range of 200∼300 Hz, and significantly decreased the F0 variability below 3 Hz, which has been reported to be associated with enhanced auditory feedback in our previous research. The auditory masking not only significantly increased the low-frequency F0 variability, but also significantly decreased the ratio of the spectral power within 200∼300 Hz to the power within 300∼1000 Hz for the vowel and sentence productions. Gender differences were found in the correlations between the degree of nasal coupling and F0 stability as well as in the LTAS characteristics in response to noise.
Variations in nasal-oral acoustic coupling not only change the formant features of speech signals, but involuntarily influence the auditory feedback control of vocal fold vibrations. Speakers tend to show improved F0 stability in response to a forward-focused voice adjustment.
研究语音焦点调整是否能改变听觉-发声反馈，进而调节言语/语音运动控制。预期使用前聚焦语音说话可增强听觉-发声反馈，从而降低嗓音基频（F0）的变异性。
要求22名健康的未经训练的成年人（10名男性和12名女性）分别以自然焦点和前聚焦持续发元音/a/，并在正常噪声掩蔽听觉条件下自然朗读鼻音、口腔音和口鼻混合音句子。同时，在噪声源外部附着一个微型加速度计，以检测发声时的鼻腔振动。进行音频录制，并使用长期平均谱（LTAS）和F0的功率谱分析进行分析。
与自然焦点元音发音和口腔音句子相比，前聚焦元音发音和鼻音句子在鼻腔加速度计幅度以及200∼300Hz范围内的频谱功率均显著增加，且在3Hz以下F0变异性显著降低，在我们之前的研究中已报道这与增强的听觉反馈有关。听觉掩蔽不仅显著增加了低频F0变异性，还显著降低了元音和句子发音中200∼300Hz范围内的频谱功率与300∼1000Hz范围内的功率之比。在鼻腔耦合程度与F0稳定性之间的相关性以及对噪声的LTAS特征方面发现了性别差异。
鼻-口声耦合的变化不仅改变语音信号的共振峰特征，还会不由自主地影响声带振动的听觉反馈控制。说话者倾向于在前聚焦语音调整时表现出更好的F0稳定性。
