Impact of Face Masks on Acoustic Measures in Patients with Hyperfunctional Voice Disorders and Normal Speakers

Purpose: Wearing face masks during the COVID-19 pandemic has become a very important hygiene measure to block or prevent respiratory droplets and infections. The purpose of this study is to explore the effect of wearing face masks on the acoustical measurement of voice and speech in patients with hyperfunctional voice disorders, and to present guidelines for wearing a mask when evaluating voice and speech.Methods: A total of 20 patients with hyperfunctional voice disorders who diagnosed with vocal nodules, muscle tension dysphonia, and adductor spasmodic dysphonia (14 females, 6 males, age=30.55±8.24) and age-and gender-matched 20 healthy adults (15 females, 5 males, age=27.31±7.52) were enrolled. All participants completed three speech tasks (sustained /a/vowel, CAPEV-3 all voiced sentence, and the ‘Kaeul’ standard passage- 2nd sentence) with their habitual pitch and loudness among the different mask conditions (No mask, surgical, and KF94). Acoustic analysis including perturbation and cepstral & spectral parameters was conducted with MDVP and ADSV.Results: For the healthy speakers, there were significantly lower in jitter (%), shimmer (%), and noise-to-harmonic (NHR) in no mask condition than in mask conditions, while there was no significantly different in perturbation measures (F0, jitter (%), shimmer (%), and NHR for patients. Vocal intensity was significantly reduced in mask-wearing conditions either surgical or KF94 mask with all speech tasks except sustained /a/ vowel phonation for patients. Cepstral peak prominence (CPP) was not significantly different among the different mask conditions in sustained /a/ vowel phonation and 3rd CAPEV sentence (all voiced sentence) in all groups. Both healthy speakers and patients showed significantly lower L/H ratio values in the no mask condition.Conclusions: Overall, in current study, wearing a mask or the type of face mask did not change time-based and cepstral acoustic parameters, while a spectral measure such as L/H ratio was significantly increased in mask-wearing conditions in patients with hyperfunctional voice disorders. These findings suggest that wearing either surgical or KF 94 masks could be a safe and relevant choice for acoustic perturbation and cepstral measures with /a/ vowel in hyperfunctional dysphonia.