Centre for Neuroscience of Speech, The University of Melbourne, 550 Swanston Street, Carlton, VIC 3053, Australia.
J Acoust Soc Am. 2020 Dec;148(6):3562. doi: 10.1121/10.0002873.
Wearing face masks (alongside physical distancing) provides some protection against infection from COVID-19. Face masks can also change how people communicate and subsequently affect speech signal quality. This study investigated how three common face mask types (N95, surgical, and cloth) affected acoustic analysis of speech and perceived intelligibility in healthy subjects. Acoustic measures of timing, frequency, perturbation, and power spectral density were measured. Speech intelligibility and word and sentence accuracy were also examined using the Assessment of Intelligibility of Dysarthric Speech. Mask type impacted the power distribution in frequencies above 3 kHz for the N95 mask, and above 5 kHz in surgical and cloth masks. Measures of timing and spectral tilt mainly differed with N95 mask use. Cepstral and harmonics to noise ratios remained unchanged across mask type. No differences were observed across conditions for word or sentence intelligibility measures; however, accuracy of word and sentence translations were affected by all masks. Data presented in this study show that face masks change the speech signal, but some specific acoustic features remain largely unaffected (e.g., measures of voice quality) irrespective of mask type. Outcomes have bearing on how future speech studies are run when personal protective equipment is worn.
佩戴口罩（与保持身体距离一起）可提供针对 COVID-19 感染的一些保护。口罩还可能改变人们的交流方式，进而影响语音信号质量。本研究调查了三种常见的口罩类型（N95、手术和布）如何影响健康受试者的语音声学分析和感知可懂度。测量了定时、频率、微扰和功率谱密度等声学参数。还使用构音障碍语音评估来检查语音可懂度以及单词和句子的准确性。口罩类型影响 N95 口罩超过 3 kHz 的频率以及手术和布口罩超过 5 kHz 的频率的功率分布。主要使用 N95 口罩时，定时和频谱倾斜的测量值会有所不同。无论口罩类型如何，倒谱和谐波噪声比都保持不变。在单词或句子可懂度测量方面，不同条件之间没有差异；但是，所有口罩都会影响单词和句子翻译的准确性。本研究提供的数据表明，口罩会改变语音信号，但某些特定的声学特征（例如，语音质量测量值）在很大程度上不受口罩类型的影响。这些结果对未来佩戴个人防护设备进行语音研究有一定影响。
