Effect of Mouth Mask and Face Shield on Speech Spectrum in Slovak Language

Abstract

In this paper, with the aim of assessing the deterioration of speech intelligibility caused by a speaker wearing a mask, different face masks (surgical masks, FFP2 mask, homemade textile-based protection and two kinds of plastic shields) are compared in terms of their acoustic filtering effect, measured by placing the mask on an artificial head/mouth simulator. For investigating the additional effects on the speaker’s vocal output, speech was also recorded while people were reading a text when wearing a mask, and without a mask. In order to discriminate between effects of acoustic filtering by the mask and mask-induced effects of vocal output changes, the latter was monitored by measuring vibrations at the suprasternal notch, using an attached accelerometer. It was found that when wearing a mask, people tend to slightly increase their voice level, while when wearing plastic face shield, they reduce their vocal power. Unlike the Lombard effect, no significant change was found in the spectral content. All face mask and face shields attenuate frequencies above 1–2 kHz. In addition, plastic shields also increase frequency components to around 800 Hz, due to resonances occurring between the face and the shield. Finally, special attention was given to the Slavic languages, in particular Slovak, which contain a large variety of sibilants. Male and female speech, as well as texts with and without sibilants, was compared.

Mask-Wearing Behaviors after Two Years of Wearing Masks Due to COVID-19 in Korea: A Cross-Sectional Study

“…Face masks negatively impact verbal communication [ 51 , 52 ], and the effects of face masks on speech recognition have been investigated both physically and psychologically. Face masks mask the acoustic signals of speech, transform the speech frequency spectra, and physically attenuate the level of speech [ 19 , 22 , 23 , 25 , 53 , 54 ]. In noisy conditions, face masks adversely affect speech recognition [ 20 , 26 , 55 , 56 ].…”

“…Complications with face masks lead to an increased risk of aspiration, difficulty in delivering a fraction of inspired oxygen, painful facial trauma, skin changes, ear pain due to the elastic straps of the mask, difficulty in expectoration, claustrophobia, and so on [ 14 , 15 , 16 , 17 ]. Furthermore, face masks degrade speech recognition [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ] and block facial communication [ 25 , 26 , 27 , 28 , 29 , 30 ]. The audiovisual speech recognition performance of transparent face masks has been studied [ 25 , 26 , 27 , 28 , 29 ].…”

The Influence of Face Masks on Verbal Communication in Persian in the Presence of Background Noise in Healthcare Staff

“…Our finding is similar to the results reported by Corey et al [ 9 ] who showed face masks had little effect on sound below 1 kHz, modest attenuation between 1 and 4 kHz, and strong attenuation above 4 kHz. Chmelik et al [ 10 ] also found that all face shields and masks attenuate frequencies above 1–2 kHz. Magee et al [ 1 ] reported significant differences in acoustic power distribution across relevant frequency bands for speech in all tested masks compared to no mask.…”

“…The results of another study by Corey et al [ 9 ] reported that there are fundamental differences among face masks in terms of acoustic properties. Chmelik et al [ 10 ] reported that when people wear masks, they tend to raise their voice level. Yi et al [ 11 ] indicated that in the presence of background sound, the listeners had a lower performance than the voices of speakers wearing face masks compared to no-mask condition.…”

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

“…Sound attenuation was evaluated as the difference in the Sound Pressure Level (SPL) at 1 m from the HATS mouth with and without the mask (∆SPL). Measurements were carried out using a white noise signal, and results were analyzed in one-third of octave bands as averages between those bands that are more important for speech intelligibility [ 20 , 45 , 46 ], from around 2 kHz to 4 kHz. We included anyway two different frequency ranges from 0.4 kHz to 5 kHz and from 1.6 kHz to 5.0 kHz, respectively, to have a clear picture of the performance of the different masks in broader ranges.…”