Effects of face masks on acoustic analysis and speech perception: Implications for peri-pandemic protocols.

Wearing face masks (alongside physical distancing) provides some protection against infection from COVID-19. Face masks can also change how people communicate and subsequently affect speech signal quality. This study investigated how three common face mask types (N95, surgical, and cloth) affected acoustic analysis of speech and perceived intelligibility in healthy subjects. Acoustic measures of timing, frequency, perturbation, and power spectral density were measured. Speech intelligibility and word and sentence accuracy were also examined using the Assessment of Intelligibility of Dysarthric Speech. Mask type impacted the power distribution in frequencies above 3 kHz for the N95 mask, and above 5 kHz in surgical and cloth masks. Measures of timing and spectral tilt mainly differed with N95 mask use. Cepstral and harmonics to noise ratios remained unchanged across mask type. No differences were observed across conditions for word or sentence intelligibility measures; however, accuracy of word and sentence translations were affected by all masks. Data presented in this study show that face masks change the speech signal, but some specific acoustic features remain largely unaffected (e.g., measures of voice quality) irrespective of mask type. Outcomes have bearing on how future speech studies are run when personal protective equipment is worn.

Speech-Language Pathology Guidance for Tracheostomy During the COVID-19 Pandemic: An International Multidisciplinary Perspective.

Purpose As the COVID-19 pandemic has unfolded, there has been growing recognition of risks to frontline health care workers. When caring for patients with tracheostomy, speech-language pathologists have significant exposure to mucosal surfaces, secretions, and aerosols that may harbor the SARS-CoV-2 virus. This tutorial provides guidance on practices for safely performing patient evaluation and procedures, thereby reducing risk of infection. Method Data were collated through review of literature, guidelines, and consensus statements relating to COVID-19 and similar high-consequent infections, with a focus on mitigating risk of transmission to health care workers. Particular emphasis was placed on speech-language pathologists, nurses, and other allied health professionals. A multinational interdisciplinary team then analyzed findings, arriving at recommendations through consensus via electronic communications and video conference. Results Reports of transmission of infection to health care workers in the current COVID-19 pandemic and previous outbreaks substantiate the need for safe practices. Many procedures routinely performed by speech-language pathologists have a significant risk of infection due to aerosol generation. COVID-19 testing can inform level of protective equipment, and meticulous hygiene can stem spread of nosocomial infection. Modifications to standard clinical practice in tracheostomy are often required. Personal protective equipment, including either powered air-purifying respirator or N95 mask, gloves, goggles, and gown, are needed when performing aerosol-generating procedures in patients with known or suspected COVID-19 infection. Conclusions Speech-language pathologists are often called on to assist in the care of patients with tracheostomy and known or suspected COVID-19 infection. Appropriate care of these patients is predicated on maintaining the health and safety of the health care team. Careful adherence to best practices can significantly reduce risk of infectious transmission.