Voice Acoustics and Vocal Effort in Mask-Wearing Healthcare Professionals: A Comparison Pre- and Post-Workday

Developing Educational Health Modules to Improve Vocal Wellness in Mask-Wearing Occupational Voice Users

OBJECTIVE

To develop educational modules to improve vocal wellness and optimize communication in mask-wearing occupational voice users.

METHODS

Module development focused on identifying accurate, understandable, and actionable steps to improve vocal wellness in the workplace. We i) interviewed eight voice-specialized speech-language pathologists and researchers on current speech and voice recommendations for mask-wearers, ii) developed educational content using the standardized Patient Education Materials Assessment Tool (PEMAT), iii) assessed the ability of nine mask-wearing community members to learn educational content, and iv) compared behavioral, acoustical, and perceptual changes in four mask-wearing healthcare professionals following educational training.

RESULTS

We created three educational modules that described key vocal health and communication strategies, including microphone amplification, postural alignment, clear speech, hydration, vocal naps, and vocal warm-ups. PEMAT scores were 96% and 93% on understandability and actionability, respectively. Mask-wearing healthcare professionals increased use of 4 out of the 6 strategies following educational training and were able to retain information at rates >90% at 1-week follow-up.

CONCLUSIONS

We developed a set of free-to-use educational modules to promote vocal wellness among mask-wearing occupational voice users (see VSMechLab.com). Future work should examine the impact of these strategies on voice measures in a larger group of mask-wearing community members.

Which Mask, N95 or Surgical Mask, Causes Hoarseness in Healthcare Workers?

OBJECTIVES

This study aimed to determine the impact of different types of masks on the voices of healthcare professionals who had to wear masks for an extended amount of time during the pandemic period and had a healthy voice.

METHODS

Our research included 41 healthcare workers. The participants were separated into two groups: surgical (n = 21) and N95 mask users (n = 20). Healthcare workers evaluated masks before and after wearing them for at least 8 hours throughout the workday. All subjects had a videolaryngoscopic examination; the Voice Handicap Index-10 (VHI-10), GRBAS, acoustic voice analysis (F0, jitter%, shimmer%, noise/harmonic ratio, relative average perturbation [RAP]), aerodynamic measures (maximum phonation time, MPT), and blood oxygen saturation were evaluated.

RESULTS

Although both groups' VHI-10 scores increased after using the mask, this rise was not statistically significant in our research. According to the GRBAS classification, voice quality deterioration was identified in 9.6% (mild-moderate) of the group using surgical masks and 15% (mild) of the group wearing N95. Only the jitter and RAP values of individuals wearing both surgical and N95 masks were determined to be statistically significant. There was no significant change in MPT following mask wear in either group. Both the surgical and N95 mask-using groups showed a substantial drop in blood oxygen saturation before and after mask usage.

CONCLUSION

There was no change in voice quality between healthcare workers wearing surgical and N95 masks. It has been noticed that voice perception and quality are affected by the mask's barrier effect rather than the kind of mask.

Prevalence of Vocal Fatigue Due to the Use of Facial Protective Gear in Teaching Medical Professionals

Since the COVID-19 pandemic, masks have become far more widely used by doctors and are now commonplace in the hospital, with many professionals still wearing them for extended amounts of time. Emerging literature describing numerous mask-related difficulties prompted the authors to conduct a study aimed at assessing the self-perceived impact on voices of teaching doctors due to facial protective gear. In this study carried out from October 2021 to March 2022, data was gathered from 170 pre-, para-, and clinical professionals who were involved in offline teaching. Over half of teaching medical professionals were found to be vocally fatigued. Pre and para-clinical professionals have greater vocal tiredness and avoidance than clinical doctors (p = 0.016). The type of mask used does not make a significant difference in degree of vocal fatigue. Individuals with lingering respiratory difficulties following COVID-19 were significantly more vocally fatigued than their recovered peers (p value for tiredness and avoidance = 0.010). Thus, teaching doctors are at risk of impaired quality of life due to vocal fatigue. Further research on vocal habits and rest practices in the study population may help identify the most effective interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04350-8.

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.

Speaking with a KN95 face mask: a within-subjects study on speaker adaptation and strategies to improve intelligibility

Mask-wearing during the COVID-19 pandemic has prompted a growing interest in the functional impact of masks on speech and communication. Prior work has shown that masks dampen sound, impede visual communication cues, and reduce intelligibility. However, more work is needed to understand how speakers change their speech while wearing a mask and to identify strategies to overcome the impact of wearing a mask. Data were collected from 19 healthy adults during a single in-person session. We investigated the effects of wearing a KN95 mask on speech intelligibility, as judged by two speech-language pathologists, examined speech kinematics and acoustics associated with mask-wearing, and explored KN95 acoustic filtering. We then considered the efficacy of three speaking strategies to improve speech intelligibility: Loud, Clear, and Slow speech. To inform speaker strategy recommendations, we related findings to self-reported speaker effort. Results indicated that healthy speakers could compensate for the presence of a mask and achieve normal speech intelligibility. Additionally, we showed that speaking loudly or clearly—and, to a lesser extent, slowly—improved speech intelligibility. However, using these strategies may require increased physical and cognitive effort and should be used only when necessary. These results can inform recommendations for speakers wearing masks, particularly those with communication disorders (e.g., dysarthria) who may struggle to adapt to a mask but can respond to explicit instructions. Such recommendations may further help non-native speakers and those communicating in a noisy environment or with listeners with hearing loss.

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.

Modeling the influence of COVID-19 protective measures on the mechanics of phonation

In an effort to mitigate the 2019 novel coronavirus disease pandemic, mask wearing and social distancing have become standard practices. While effective in fighting the spread of the virus, these protective measures have been shown to deteriorate speech perception and sound intensity, which necessitates speaking louder to compensate. The goal of this paper is to investigate via numerical simulations how compensating for mask wearing and social distancing affects measures associated with vocal health. A three-mass body-cover model of the vocal folds (VFs) coupled with the sub- and supraglottal acoustic tracts is modified to incorporate mask and distance dependent acoustic pressure models. The results indicate that sustaining target levels of intelligibility and/or sound intensity while using these protective measures may necessitate increased subglottal pressure, leading to higher VF collision and, thus, potentially inducing a state of vocal hyperfunction, a progenitor to voice pathologies.

Does the wearing of masks change voice and speech parameters?

PURPOSE

The authors aim to review available reports on the potential effects of masks on voice and speech parameters.

METHODS

A literature search was conducted using MEDLINE and Google Scholar databases through July 2021. Several targeted populations, mask scenarios and methodologies were approached. The assessed voice parameters were divided into self-reported, acoustic and aerodynamic.

RESULTS

It was observed that the wearing of a face mask has been shown to induce several changes in voice parameters: (1) self-reported-significantly increased vocal effort and fatigue, increased vocal tract discomfort and increased values of voice handicap index (VHI) were observed; (2) acoustics-increased voice intensity, altered formants frequency (F2 and F3) with no changes in fundamental frequency, increased harmonics-to-noise ratio (HNR) and increased mean spectral values in high-frequency levels (1000-8000 Hz), especially with KN95 mask; (3) aerodynamics-maximum phonatory time was assessed in only two reports, and showed no alterations.

CONCLUSION

Despite the different populations, mask-type scenarios and methodologies described by each study, the results of this review outline the significant changes in voice characteristics with the use of face masks. Wearing a mask shows to increase the perception of vocal effort and an alteration of the vocal tract length and speech articulatory movements, leading to spectral sound changes, impaired communication and perception. Studies analyzing the effect of masks on voice aerodynamics are lacking. Further research is required to study the long-term effects of face masks on the potential development of voice pathology.