Effects of surgical and FFP2 masks on vocal tract discomfort perception and on acoustic features of speech therapist's voice after a working day

BACKGROUND: Facial masks are a very effective barrier to control the spread of respiratory infectious diseases as the SAR S-CoV-2, but their prolonged use can adversely affect speech understanding and physiological vocal emission. Aim of this work was to analyze, through objective and subjective outcome measures, the impact that different types of facial masks (surgical and FFP2) have on the voice and on the perception of vocal discomfort, in a group of speech therapists. METHODS: Eleven female speech therapists were enrolled and assessed at the beginning and end of an 8-hour work shift during which they wore the surgical mask or the FFP2 mask. The main outcomes meauseres included: the maximum phonation time, acoustic analysis (F0, Jitter, shimmer, HT N ratio, mean-dB intensity, Fmin Hz, Fmax Hz) the Italian version of the Vocal Tract Discomfort Scale (I-VTD) and a self-assessment questionnaire specifically developed for this study. RESULTS: Most of the acoustic index values were significantly increased at the end of the working day, especially after wearing the FFP2 mask. Similarly, the mean total scores on the I-VTD Scale and the self-assessment questionnaire were significantly higher after wearing the FFP2 mask. Specifically, subjects complained of feeling of irritability, tightness, dryness, perception of burning, tickling/itching, vocal fatigue, altered voice, vocal tension and difficulty in pneumophonic coordination. CONCLUSIONS: Because of their composition and strong adherence to the face, FFP2 masks, used continuously for 8 hours, have a significantly worse impact than the surgical ones on both the voice and the perception of vocal discomfort.