Effect of Face Masks on Speech Intelligibility

With the advent of COVID, the wearing of face covering has been obligatory in both medical and everyday life. This paper describes three experiments undertaken to establish the effect of face coverings on speech sound power, speech directivity and speech intelligibility. The experiments used two different approaches acoustic measurements and word scores. The face coverings assessed were a 'standard blue' surgical mask, a typical fabric mask, and a plastic transparent visor. The results showed that non-native English speakers had by far the most difficulty in comprehending the English language speech when face coverings were worn in speech intelligibility tests, as measured using phonetically balanced word lists. All the masks were found to noticeably affect speech intelligibility, with the surgical mask having the least detrimental effect. The results are also compared to objective measurements of their physical acoustics characteristics to establish their performance.