Hearing What You Can't See: Influence of Face Masks on Speech Perception and Eye Movement by Adults With Hearing Loss

The aim of the study was to analyze how face masks influence speech perception and time spent looking at the speaker's mouth and eyes by adults with and without hearing loss.

Twenty participants with hearing loss and 20 without were asked to repeat Spanish words presented in various conditions, including different types of face masks (no mask, transparent window mask, and opaque mask FFP2) and presentation modes (audiovisual, video only, and audio only). Recognition accuracy and the percentage of time looking at the speaker's eyes and mouth (dwell time) were measured.

In the audiovisual condition, participants with hearing loss had significantly better word recognition scores when the speaker wore no mask compared to when they wore an opaque face mask. However, there were no differences between the transparent mask and no mask conditions. For those with typical hearing, the type of face mask did not affect speech recognition. Audiovisual presentation consistently improved speech recognition for participants with hearing loss across all face mask conditions, but for those with typical hearing, it only improved compared to video-only mode. These participants demonstrated a ceiling effect in audiovisual and audio-only modes. Regarding eye movement patterns, participants spent less time looking at the speaker's mouth and more time at the eyes when the speaker wore an opaque mask compared to no mask or a transparent mask.

The use of transparent face masks (ClearMask-type model) is recommended in contexts where face masks are still used (hospitals) to prevent the hindering effect of opaque masks (FFP2-type model) in speech perception among people with hearing loss, provided that any fogging of the window of the transparent mask is controlled by wiping it off as needed and the light is in front of the speaker to minimize shadows.