The burden of face masks on speech in Parkinson's disease: Impact of clear and loud speech styles

Abstract

Face masks, now ubiquitous as a means of reducing COVID-19 transmission, have been shown to act as a low pass acoustic filter on speech. People with Parkinson’s disease (PwPD) and dysarthria may be especially vulnerable to the detrimental effects of masks, which may have negative consequences on spoken communication. The speech of PwPD has been shown to have lower concentrations of high frequency spectral energy and is perceptually characterized by a low speech volume and a breathy-hoarse voice quality. Increased vocal effort may aid in overcoming the filtering effects of masks. The purpose of this study was to quantify the effects of three masks (none, surgical, KN95) and three speech styles (habitual, clear, and loud) on the spectral characteristics of speech in PD. Fifteen PwPD and fifteen controls read aloud sentences with and without masks in three speech conditions. Measures of spectral tilt were taken from the long-term average spectra and modelled as a function of group, mask, and style. While both masks were associated with overall attenuation (steeper spectral tilt), a greater decrease was found for the PwPD (group by mask interaction). Loud speech, followed by clear speech, was effective in overcoming these effects for both groups.