How Face Masks Interfere With Speech Understanding of Normal-Hearing Individuals: Vision Makes the Difference

To investigate the effects of wearing a simulated mask on speech perception of normal-hearing subjects.

Prospective cohort study.

University hospital.

Fifteen normal-hearing, native German speakers (8 female, 7 male).

Different experimental conditions with and without simulated face masks using the audiovisual version of the female German Matrix test (Oldenburger Satztest, OLSA).

Signal-to-noise ratio (SNR) at speech intelligibility of 80%.

The SNR at which 80% speech intelligibility was achieved deteriorated by a mean of 4.1 dB SNR when simulating a medical mask and by 5.1 dB SNR when simulating a cloth mask in comparison to the audiovisual condition without mask. Interestingly, the contribution of the visual component alone was 2.6 dB SNR and thus had a larger effect than the acoustic component in the medical mask condition.

As expected, speech understanding with face masks was significantly worse than under control conditions. Thus, the speaker's use of face masks leads to a significant deterioration of speech understanding by the normal-hearing listener. The data suggest that these effects may play a role in many everyday situations that typically involve noise.