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

Abstract

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

Study design: Prospective cohort study.

Setting: University hospital.

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

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

Main outcome measures: Signal-to-noise ratio (SNR) at speech intelligibility of 80%.

Results: 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.

Conclusions: 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.