Improving the measurement and acoustic performance of transparent face masks and shields

The beneficial effect of transparent surgical masks on the communication of adults with hearing loss within clinical settings

Purpose: The study examined the benefits of transparent versus non-transparent surgical masks on the speech intelligibility in quiet of adult cochlear implant (CI) users, in conjunction with patient preferences and the acoustic effects of the different masks on the speech signal.

Methods: Speech tracking test (STT) scores and acoustical characteristics were measured in quiet for live speech in three different conditions, without mask, with a non-transparent surgical mask and with a transparent surgical mask. Patients were asked about their experience with the face masks. The study sample consists of 30 patients using a cochlear implant.

Results: We found a significant difference in speech perception among all conditions, with the speech tracking scores revealing a significant advantage when switching from the non-transparent surgical mask to the transparent one. The transparent surgical mask, although it does not transmit high frequencies effectively, seems to have minimal effect on speech comprehension in practice when lip movements are visible. This substantial benefit is further emphasized in the questionnaire, where 82% of the patients express a preference for the transparent surgical mask.

Conclusion: The study highlights significant benefits for patients in speech intelligibility in quiet with the use of medically safe transparent facemasks. Transitioning from standard surgical masks to transparent masks demonstrates highly significant effectiveness and patient satisfaction for patients with hearing loss. This research strongly advocates for the implementation of transparent masks in broader hospital and perioperative settings.

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.

Perceptions of Adults With Hearing Loss About the Communication Difficulties Generated by the COVID-19 Preventive Measures: A Qualitative Study

PURPOSE

The COVID-19 pandemic led to the implementation of preventive measures that exacerbated communication difficulties for individuals with hearing loss. This study aims to explore the perception of adults with hearing loss about the communication difficulties caused by the preventive measures and about their experiences with communication 1 year after the adoption of these preventive measures.

METHOD

Individual semistructured interviews were conducted via videoconference with six adults who have hearing loss from the province of Québec, Canada. Data were examined using qualitative content analysis.

RESULTS

The study found that face masks and in-person work (i.e., in opposition to remote work) were important barriers to communication because of hindered lipreading and competing noise in many workplaces. In contrast, preventive measures that allowed visual information transmission (e.g., transparent face masks, fixed plastic partitions) were considered favorable for communication. Communication partners were perceived as playing an important role in communication success with preventive measures: Familiar communication partners improved communication, whereas those with poor attitude or strategies hindered communication. Participants found that videoconferences could provide satisfactory communication but were sometimes hindered by issues such as bad audiovisual quality or too many participants.

CONCLUSIONS

This study identified reduced access to speech reading and lack of general awareness about hearing issues as key barriers to communication during the pandemic. The decreased communication capabilities were perceived to be most problematic at work and during health appointments, and tended to cause frustration, anxiety, self-esteem issues, and social isolation. Suggestions are outlined for current and future public health measures to better consider the experience of people with hearing loss.

A Transparent Mask and Clear Speech Benefit Speech Intelligibility in Individuals With Hearing Loss

PURPOSE

The purpose of the study is to investigate the impacts of a surgical mask and a transparent mask on audio-only and audiovisual speech intelligibility in noise (i.e., 0 dB signal-to-noise ratio) in individuals with mild-to-profound hearing loss. The study also examined if individuals with hearing loss can benefit from using a transparent mask and clear speech for speech understanding in noise.

METHOD

Thirty-one individuals with hearing loss (from 22 to 74 years old) completed keyword identification tasks to measure face-masked speech intelligibility in noise. A mixed-effects logistic regression model was used to examine the effects of face masks (no mask, transparent mask, surgical mask), presentation modes (audio only, audiovisual), speaking styles (conversational, clear), noise type (speech-shaped noise [SSN], four-talker babble [4-T babble]), hearing groups (mild hearing loss [MHL], greater than MHL: GHL), and their interactions on binary accuracy of keyword identification.

RESULTS

In the audio-only mode, the GHL group showed reduced speech intelligibility regardless of other factors, whereas the MHL group showed decreased speech intelligibility for the transparent mask more than for the surgical mask. The use of a transparent mask was advantageous for both hearing loss groups. Clear speech remediated the detrimental effects of face masks on speech intelligibility in noise. Both groups tended to perform better in SSN versus 4-T babble.

CONCLUSIONS

The findings indicate that, when using face masks, either a transparent mask or a surgical mask negatively affects speech understanding in noise for individuals with hearing loss. Using a transparent mask and clear speech could be a potential solution to improve speech intelligibility in communication with face masks in noise.

The effects of face masks on speech-in-speech recognition for children and adults

OBJECTIVES

This study explored the effects of different face masks on school-age children's and young adults' word recognition.

DESIGN

Speech recognition thresholds were measured adaptively in a two-talker speech masker using a closed-set picture pointing task. Target words were recorded by a female talker in five conditions: no mask, transparent mask, face shield, N95 mask and surgical mask.

STUDY SAMPLES

Thirty children (8-12 years) and 25 adults (18-25 years) with normal hearing.

RESULTS

Both children's and adults' word recognition was most negatively impacted by the face shield. Children's recognition was also impaired by the transparent mask. No negative effects were observed for the N95 or surgical mask for either age group.

CONCLUSION

School-age children, like young adults, are negatively affected by face masks when recognising speech in a two-talker speech masker, but the effects depend on the type of face mask being worn. Acoustic analyses suggest that the reflective materials used for masks impact speech signal quality and impair word recognition.

Listening Effort and Speech Perception Performance Using Different Facemasks

PURPOSE

The aim of this study was to assess the effect of eight different facemasks on speech perception and listening effort in listeners with normal hearing (NH) and hearing loss by manipulating both mask type and background noise levels.

METHOD

Forty adults listened to Quick Speech-in-Noise Test sentences recorded by a female talker through eight different facemasks including a baseline condition with no mask. Listeners were tested in the sound field positioned 6 ft from the loudspeaker. Signal-to-noise ratio (SNR) loss and listening effort were measured.

RESULTS

Listeners with NH exhibited a mild SNR loss, whereas those with hearing loss experienced a moderate SNR loss. Scores for the mild hearing loss group were significantly poorer (higher) than those with slight hearing loss. Speech perception performance was best in the no mask, KN95, and surgical mask conditions and poorest in the cloth mask and cloth mask plus face shield conditions for all groups. As listening effort decreased, speech perception increased for all groups.

CONCLUSIONS

The impact of different types of facemasks on speech perception in noise was demonstrated in this study indicating that as the SNR was reduced, listening effort increased and speech perception performance decreased for listeners with NH and slight/mild hearing loss. No mask, KN95, and surgical masks had the least impact on performance, whereas cloth masks posed a significant detriment to communication. If communication is to occur in a background of noise while wearing masks, a KN95 mask and an SNR of at least +15 dB is recommended regardless of hearing status.

Effects of Face Masks on Physiological Parameters and Voice Production during Cycling Activity

This study investigates the effects of face masks on physiological and voice parameters, focusing on cyclists that perform incremental sports activity. Three healthy male subjects were monitored in a climatic chamber wearing three types of masks with different acoustic properties, breathing resistance, and air filtration performance. Masks A and B were surgical masks made of hydrophobic fabric and three layers of non-woven fabric of 100% polypropylene, respectively. Mask S was a multilayer cloth mask designed for sports activity. Mask B and Mask S behave similarly and show lower sound attenuation and sound transmission loss and lower breathing resistance than Mask A, although Mask A exhibits slightly higher filtration efficiency. Similar cheek temperatures were observed for Masks A and B, while a significantly higher temperature was measured with Mask S at incremental physical activity. No differences were found between the masks and the no-mask condition for voice monitoring. Overall, Mask B and Mask S are suitable for sports activities without adverse effects on voice production while ensuring good breathing resistance and filtration efficiency. These outcomes support choosing appropriate masks for sports activities, showing the best trade-off between breathing resistance and filtration efficiency, sound attenuation, and sound transmission loss.