Visual and Acoustic Aspects of Face Masks Affect Speech Intelligibility in Listeners with Different Hearing Statuses

Background: When speaking while wearing a face mask, sound transmission is attenuated, and visual cues are lost due to the covered facial movements of the speaker. In this study, we investigated the extent to which different face masks alter speech intelligibility in individuals with different degrees of hearing impairment. Methods: A total of fifty participants were divided into four hearing status groups according to the degree of hearing loss: normal levels (16), mild (13), moderate (11), and severe (10). A modified version of the Audiovisual German Matrix Sentence Test (AV-OLSA) was used to assess speech perception in noise in five conditions (audiovisual, audio-only, visual-only, surgical mask, and FFP2 mask). Results: Our results show that acoustic attenuations of face masks cause a small but similar decrease in speech reception thresholds (SRTs) in listeners of different hearing statuses. The effect of visual cues (visual benefit) on SRTs was stronger than the effect of acoustic attenuation but also did not differ significantly between the different hearing status groups, with a median difference of 1.5 dB for mild hearing loss, 2.9 dB for moderate hearing loss, and 2.7 dB for severe hearing loss. The best-aided hearing status did not correlate with visual benefit. Conclusions: Our research confirms the importance of providing visual cues for speech reception in noisy environments, especially for individuals with impaired hearing, regardless of their degree of hearing loss.