The Effect of Conventional and Transparent Surgical Masks on Speech Understanding in Individuals with and without Hearing Loss

Abstract

Background: It is generally well known that speech perception is often improved with integrated audiovisual input whether in quiet or in noise. In many health-care environments, however, conventional surgical masks block visual access to the mouth and obscure other potential facial cues. In addition, these environments can be noisy. Although these masks may not alter the acoustic properties, the presence of noise in addition to the lack of visual input can have a deleterious effect on speech understanding. A transparent ("see-through") surgical mask may help to overcome this issue.

Purpose: To compare the effect of noise and various visual input conditions on speech understanding for listeners with normal hearing (NH) and hearing impairment using different surgical masks.

Research design: Participants were assigned to one of three groups based on hearing sensitivity in this quasi-experimental, cross-sectional study.

Study sample: A total of 31 adults participated in this study: one talker, ten listeners with NH, ten listeners with moderate sensorineural hearing loss, and ten listeners with severe-to-profound hearing loss.

Data collection and analysis: Selected lists from the Connected Speech Test were digitally recorded with and without surgical masks and then presented to the listeners at 65 dB HL in five conditions against a background of four-talker babble (+10 dB SNR): without a mask (auditory only), without a mask (auditory and visual), with a transparent mask (auditory only), with a transparent mask (auditory and visual), and with a paper mask (auditory only).

Results: A significant difference was found in the spectral analyses of the speech stimuli with and without the masks; however, no more than ∼2 dB root mean square. Listeners with NH performed consistently well across all conditions. Both groups of listeners with hearing impairment benefitted from visual input from the transparent mask. The magnitude of improvement in speech perception in noise was greatest for the severe-to-profound group.

Conclusions: Findings confirm improved speech perception performance in noise for listeners with hearing impairment when visual input is provided using a transparent surgical mask. Most importantly, the use of the transparent mask did not negatively affect speech perception performance in noise.