A pilot study on the impact of wearing powered air-purifying respirators on speech intelligibility

Powered air-purifying respirators (PAPR) have become an increasingly utilized form of respiratory protection against highly infectious aerosols. In the United States, PAPRs have been used in high-level clinical isolation settings to care for patients infected with viral hemorrhagic fevers and, more recently, during the COVID-19 pandemic. PAPRs have long been used for biocontainment care and experienced increased use during the pandemic because they provide full-face visibility and eye and respiratory protection. Despite their extended use, limited studies have explored the operational usability and limitations of these devices, especially during patient care and communication. For this pilot study, the speech intelligibility of two commonly used PAPR brands was examined in a clinical setting using some requirements from the National Institute for Occupational Safety and Health (NIOSH) standard testing procedure (NIOSH TEB-CBRN-APR-STP-0313 Determination of Communication Performance Test For Speech) for determining communication performance for speech conveyance in PAPRs. A total of 19 study participants were split into 17 speakers and two listeners. Speakers were assigned to test groups. Each speaker was provided with a word list, while listeners were provided with a response list. A modified rhyme test (MRT) was conducted to determine the communication performance rating of each PAPR brand. The 3M PAPR had a higher performance rating than MAXAIR across all test groups, despite having a 5 dBA higher internal noise. The difference in the mean performance rating of 3M (75) was significantly higher than that of MAXAIR (59) (95% CI: -23.66-9.09). Overall, the 3M PAPR was strongly preferred among study participants in terms of comfort, fit, and noise level. Interventions such as incorporating communication devices are of interest for future study, and an assessment of additional limitations is needed to optimize PAPR use in clinical care activities.