COVID-19: Acoustic Measures of Voice in Individuals Wearing Different Facemasks

Abstract

Aim The global health pandemic caused by the SARS-coronavirus 2 (COVID-19) has led to the adoption of facemasks as a necessary safety precaution. Depending on the level of risk for exposure to the virus, the facemasks that are used can vary. The aim of this study was to examine the effect of different types of facemasks, typically used by healthcare professionals and the public during the COVID-19 pandemic, on measures of voice. Methods Nineteen adults (ten females, nine males) with a normal voice quality completed sustained vowel tasks. All tasks were performed for each of the six mask conditions: no mask, cloth mask, surgical mask, KN95 mask and, surgical mask over a KN95 mask with and without a face shield. Intensity measurements were obtained at a 1ft and 6ft distance from the speaker with sound level meters. Tasks were recorded with a 1ft mouth-to-microphone distance. Acoustic variables of interest were fundamental frequency (F0), and formant frequencies (F1, F2) for /a/ and /i/ and smoothed cepstral peak prominence (CPPs) for /a/. Results Data were analyzed to compare differences between sex and mask types. There was statistical significance between males and females for intensity measures and all acoustic variables except F2 for /a/ and F1 for /i/. Few pairwise comparisons between masks reached significance even though main effects for mask type were observed. These are further discussed in the article. Conclusion The masks tested in this study did not have a significant impact on intensity, fundamental frequency, CPPs, first or second formant frequency compared to voice output without a mask. Use of a face shield seemed to affect intensity and CPPs to some extent. Implications of these findings are discussed further in the article.

Does the wearing of masks change voice and speech parameters?

“…The harmonics-to-noise ratio (HNR) values were significantly increased with the wearing of a mask, either a surgical or a KN95, when compared to the no-mask condition [8,13]; it was also increased after a mask-wearing workday comparing with the pre-workday value [11]. However, cepstral peak prominence (CPP) showed none or minimally changes with mask-wearing in all studies [5,7,8,13].…”

“…A total of 1005 people were assessed for voice changes. Of the nine selected articles, six [5,7,8,10,11,13] outlined acoustic parameters, four [6,9,11,12] described self-reported vocal characteristics, and only two [8,10] assessed voice aerodynamics. None of them described all three vocal domains, neither perceptual voice evaluation.…”

“…Fundamental frequency (F0) values did not seem to be significantly changed by the wearing of a mask [5,7,8,10], although a significant decrease in relative fundamental frequency (RFF) offset ten was observed in mask wearers after a workday (p = 0,001), especially when wearing KN95 [11].…”

“…Overall, when comparing mask and no-mask scenarios (regardless of the type of mask), it was observed a significant increase in vocal intensity while wearing a face mask in all [5,7,8,11] but two of the six studies performing acoustic voice evaluation [10,13].…”

“…Some studies also measured formants frequency F1, F2 and F3 [5,8]. Formant frequency F2 showed to be altered in Joshi et al [5] decreasing in males with KSF scenario (face shield over surgical mask and KN95), and increased in females wearing a surgical mask when comparing with other mask-type scenarios.…”