Effect of Face Mask on Voice Production During COVID-19 Pandemic: A Systematic Review

The impact of face coverings on audio-visual contributions to communication with conversational speech

The use of face coverings can make communication more difficult by removing access to visual cues as well as affecting the physical transmission of speech sounds. This study aimed to assess the independent and combined contributions of visual and auditory cues to impaired communication when using face coverings. In an online task, 150 participants rated videos of natural conversation along three dimensions: (1) how much they could follow, (2) how much effort was required, and (3) the clarity of the speech. Visual and audio variables were independently manipulated in each video, so that the same video could be presented with or without a superimposed surgical-style mask, accompanied by one of four audio conditions (either unfiltered audio, or audio-filtered to simulate the attenuation associated with a surgical mask, an FFP3 mask, or a visor). Hypotheses and analyses were pre-registered. Both the audio and visual variables had a statistically significant negative impact across all three dimensions. Whether or not talkers' faces were visible made the largest contribution to participants' ratings. The study identifies a degree of attenuation whose negative effects can be overcome by the restoration of visual cues. The significant effects observed in this nominally low-demand task (speech in quiet) highlight the importance of the visual and audio cues in everyday life and that their consideration should be included in future face mask designs.

Scalable, solvent-free transparent film-based air filter with high particulate matter 2.5 filtration efficiency

Over the course of the COVID-19 pandemic, people have realized the importance of wearing a mask. However, conventional nanofiber-based face masks impede communication between people because of their opacity. Moreover, it remains challenging to achieve both high filtration performance and transparency through fibrous mask filters without using harmful solvents. Herein, scalable transparent film-based filters with high transparency and collection efficiency are fabricated in a facile manner by means of corona discharging and punch stamping. Both methods improve the surface potential of the film while the punch stamping procedure generates micropores in the film, which enhances the electrostatic force between the film and particulate matter (PM), thereby improving the collection efficiency of the film. Moreover, the suggested fabrication method involves no nanofibers and harmful solvents, which mitigates the generation of microplastics and potential risks for the human body. The film-based filter provides a high PM2.5 collection efficiency of 99.9 % while maintaining a transparency of 52 % at the wavelength of 550 nm. This enables people to distinguish the facial expressions of a person wearing a mask composed of the proposed film-based filter. Moreover, the results of durability experiments indicate that the developed film-based filter is anti-fouling, liquid-resistant, microplastic-free and foldability.

The Impact of Protective Face Coverings on Acoustic Markers in Voice: A Systematic Review and Meta-Analysis

BACKGROUND

Wearing respiratory protective masks (RPMs) has become common worldwide, especially in healthcare settings, since the onset of the COVID-19 pandemic. Hypotheses have suggested that sound transmission could be limited by RPMs, which possibly affects the characteristics of acoustic energy and speech intelligibility. The objective of this study was to investigate the effect of RPMs on acoustic measurements through a systematic review with meta-analysis.

METHODS

Five database searches were conducted, ranging from their inception to August 2023, as well as a manual search. Cross-sectional studies were included that provided data on widely used gender-independent clinical acoustic voice quality measures (jitter, shimmer, HNR, CPPS, and AVQI) and habitual sound pressure level (SPL).

RESULTS

We found nine eligible research studies with a total of 422 participants who were compared both without masks and with different types of masks. All included studies focused on individuals with vocally healthy voices, while two of the studies also included those with voice disorders. The results from the meta-analysis were related to medical/surgical and FFP2/(K)N95 masks. None of the acoustic measurements showed significant differences between the absence and presence of masks (p > 0.05). When indirectly comparing both mask types, statistical significance was identified for parameters of jitter, HNR, CPPS and SPL (p < 0.001).

CONCLUSIONS

The present meta-analysis indicates that certain types of RPMs have no significant influence on common voice quality parameters and SPL compared to recordings without masks. Nevertheless, it is plausible that significant differences in acoustic parameters might exist between different mask types. Consequently, it is advisable for the clinical practice to always use the same mask type when using RPMs to ensure high comparability and accuracy of measurement results.

How Does Long Term Use of Surgical Face Mask Affect the Voice in Normophonic Subjects?

OBJECTIVES

To assess the effects of the longterm-use of surgical face mask (SFM) on acoustic and auditory-perceptual voice parameters in normophonic subjects without any known risk factor related to voice disorders.

MATERIALS AND METHODS

Of 73 normophonic subjects who were previously included in a couple of studies before the COVID-19 outbreak, 25 people (18 female and 7 male) who were free of any known risk factor related to voice disorders during the outbreak were re-evaluated to assess the long-term effect of SFM on voice by using acoustic (mean F0, Jitter-local, Shimmer-local, Cepstral Peak Prominence (CPP), Noise to Harmonic Ratio (NHR), maximum phonation time (MPT)) and auditory-perceptual (Consensus Auditory-Perceptual Evaluation of Voice, CAPE-V) parameters and those data found in SFM period were compared with the previous (preSFM) data. MPT and acoustic data were analyzed by PRAAT software.

RESULTS

It was seen that the mean F0 value presented a significant increase, while Jitter-local and Intensity values revealed a significant decrease in females after 2 years pass with SFM use (average 22.52 ± 0.18 months).In males, only a significant decrease in Jitter-local was detected.

CONCLUSIONS

This study is the first longitudinal investigation on the effects of SFM use on acoustic and auditory-perceptual measures of voice. The data in this study, revealed that long-term use of SFM would not appear to be negatively affecting the acoustic parameters of the voice in normophonic subjects (particularly females) without any related risk factors such as tobacco use, reflux, and etc.

Speaking with mask in the COVID-19 era: Multiclass machine learning classification of acoustic and perceptual parameters

The intensive use of personal protective equipment often requires increasing voice intensity, with possible development of voice disorders. This paper exploits machine learning approaches to investigate the impact of different types of masks on sustained vowels /a/, /i/, and /u/ and the sequence /a'jw/ inside a standardized sentence. Both objective acoustical parameters and subjective ratings were used for statistical analysis, multiple comparisons, and in multivariate machine learning classification experiments. Significant differences were found between mask+shield configuration and no-mask and between mask and mask+shield conditions. Power spectral density decreases with statistical significance above 1.5 kHz when wearing masks. Subjective ratings confirmed increasing discomfort from no-mask condition to protective masks and shield. Machine learning techniques proved that masks alter voice production: in a multiclass experiment, random forest (RF) models were able to distinguish amongst seven masks conditions with up to 94% validation accuracy, separating masked from unmasked conditions with up to 100% validation accuracy and detecting the shield presence with up to 86% validation accuracy. Moreover, an RF classifier allowed distinguishing male from female subject in masked conditions with 100% validation accuracy. Combining acoustic and perceptual analysis represents a robust approach to characterize masks configurations and quantify the corresponding level of discomfort.

Effects of Virtual Teaching on Swedish Teachers' Voices During the COVID-19 Pandemic

PURPOSE

Since the beginning of 2020, teachers all over the world have had to switch over to virtual teaching because of the COVID-19 pandemic. This change of teaching mode has unknown consequences on the vocal health of teachers who already experience voice disorders at a rate nearly double that of the general population. Therefore, the purpose of this study is to investigate teachers' self-reported voice problems during virtual teaching compared to face-to-face teaching and how they are associated to perceived risk factors in the work environment.

METHOD

Participants included 141 teachers (49 males, 92 females) in high schools and higher education in Sweden who responded to an internet-based survey. Information was collected about participants' self-reported voice handicap using a translated version of the Voice Handicap Index-10 (VHI-10). Information about self-reported VTD (Vocal Tract Discomfort) symptoms and dysphonia was collected in regard to both modes of teaching (virtual vs face-to- face). The survey also included questions on risk factors related to vocal health.

RESULTS

Self-reported voice handicap and VTD symptoms were slightly lower during periods of virtual teaching compared to periods of face-to-face teaching. There was a lower frequency of dysphonia symptoms during virtual teaching compared to face-to- face teaching, however the difference was not statistically significant. In addition, 34% of teachers reported experiencing more voice problems when teaching face-to-face while 15% reported more voice problems when teaching virtually. The most reported VTD symptoms during both virtual and face-to-face teaching were having a dry and a tight throat. The dysphonia symptoms with the highest reported frequency were a tense voice and hoarseness in both modes of teaching. Risk factors associated with higher prevalence of voice symptoms and/or higher levels of voice handicap during virtual teaching were air quality and straining the voice while teaching face-to-face. In addition, those teachers who reported more voice problems while teaching virtually also reported feeling more stressed.

CONCLUSION

The results showed a slight decrease in voice symptoms and voice handicap during virtual teaching compared to face-to-face teaching. Although multifactorial, results suggest that a potential positive effect may be attributed to better air quality in the work environment and more favorable acoustic conditions preventing teachers from straining their voice.

How the COVID-19 Pandemic Muted and Remixed the World's Acoustics for a While

PURPOSE OF REVIEW

This review aims to analyze the effects of the pandemic on the world's sound environment.

RECENT FINDINGS

The confinements associated with the pandemic led to a reduction in sound levels worldwide and a change in the perception of soundscapes in the absence of traffic noise and human-generated noise.

SUMMARY

In response to the COVID-19 pandemic, many countries and regions around the world adopted a series of interventions in 2020 that have been referred to as "lockdown" or "confinement." These sets of restrictions had a clear and obvious consequence derived from the absence of people in the streets and the reduction of daily activity and commuting, which caused an unprecedented silencing on a large scale. Along with the silence that ensued, the pandemic and the confinements affected acoustics and our relationship with sounds on different scales. In the cities, this phenomenon had a strong reduction in acoustic intensity due to the absence of vehicles on the streets. Perhaps this was more perceptible in our neighborhoods, with notable changes in their soundscapes, first due to the absence of people in the streets and later due to more outdoor activity derived from the fear of the spread of the virus in indoor spaces. The longer periods of time spent in our homes during the lockdowns also highlighted the importance of sound insulation in buildings and the acoustic conditioning of our schools or homes.

Reliability of Acoustic Measures in Dysphonic Patients With Glottic Insufficiency and Healthy Population: A COVID-19 Perspective

OBJECTIVES

The COVID-19 pandemic has affected the voice assessment protocols for dysphonic patients. In this study, we compared the changes in acoustic measures of the healthy population as well as dysphonic patients due to glottic insufficiency between the pandemic period requiring face masks and the prepandemic period when the masks were not essential. The clinical reliability of the acoustic measures with and without face masks was explored.

METHODS

A total of 120 patients (age = 42.3 ± 11.9 yrs) with glottic insufficiencies such as UVFP and sulcus vocalis and 40 healthy population (age = 40.5 ± 11.2 yrs) cohorts were enrolled during the pandemic period. Age- and gender-matched 120 patients and 40 healthy population cohorts who underwent voice assessment without face masks before the pandemic were enrolled as prepandemic controls. Acoustic measures and overall severity estimates of vowel and speech samples were compared, which included cepstral peak prominence (CPP), L/H spectral ratio (SR), their standard deviations, F0, jitter percent (Jitt), shimmer percent (Shim), noise-to-harmonic ratio (NHR), Cepstral Spectral Index of Dysphonia (CSID), and Acoustic Psychometric Severity Index of Dysphonia.

RESULTS

Both patients and healthy cohorts showed higher SRv and SRs but lower CSIDv during the pandemic compared to the prepandemic period. F0 of the healthy male controls during the pandemic was higher than during the prepandemic periods, while the CSIDs was lower for the pandemic period. The pandemic patient cohort showed lower σSRs compared to the prepandemic patient cohort. When the acoustic measures of patients were compared to the healthy population cohort, the patient cohort showed lower CPP and σCPPs, while higher σCPPv, Jitt, Shim, and NHR during both pandemic and prepandemic period. Overall, the area under the curve of the acoustic measures and overall severity estimates was similar between the mask and non-mask groups, although the AUC of the SR measures was poor.

CONCLUSIONS

Wearing face masks during the pandemic did not compromise the overall reliability of the acoustic analysis in patients with glottic insufficiency, suggesting the current protocol of acoustic analysis can be carried out reliably while wearing a mask to ensure safety in the pandemic era.

The Effects of Mask Usage on Reported Vocal Health of Educators

OBJECTIVE

To investigate the self-reported effects of mask usage on vocal fatigue and number of vocal complaints of high school and college educators.

METHOD

Forty teachers at high schools and universities who reported using masks to teach in person during the Spring 2020 to Fall 2020 semesters completed an anonymous survey regarding self-report of teaching history, vocal use, vocal complaints, and vocal health. Responses were analyzed using descriptive statistics and t tests.

RESULTS

Survey participants reported an increase in all forms of vocal complaints investigated despite an increase in amplification use. Participants also reported a decrease in daily water consumption between eight and 16 ounces of water when wearing a mask in the classroom compared to teaching prior to coronavirus disease 2019. Participants also reported a significant increase in vocal effort while teaching in a mask (P < 0.001).

CONCLUSION

Educators reported a significant effect of increased vocal complaints and decreased water intake while wearing masks. The decrease in water consumption and increase in vocal effort may lead to more frequent vocal complaints in teachers at the high school and college level.