Effect of Powered Air‐Purifying Respirators on Speech Recognition Among Health Care Workers

Abstract

Powered air-purifying respirators (PAPRs) are used as personalized protective equipment for health care personnel. PAPRs offer health care workers added protection when dealing with patients who have high-risk infectious disease such as COVID-19. Unfortunately, PAPRs can produce notable levels of background noise. We hypothesize that PAPR use may be associated with increased hearing thresholds and impaired word discrimination and may ultimately have a negative impact on effective communication. Herein, we (1) determined sound levels generated by PAPRs and (2) measured hearing thresholds and word discrimination with and without operational PAPRs. All participants had normal hearing. When the PAPR was operational, mean ± SD thresholds increased from 4.5 ± 3.6 to 38.6 ± 5.6 dB HL ( P < .001). Word discrimination dropped from 100% in all participants in quiet to a mean 48% ± 14% with operational PAPR ( P < .001). Thus, we find that use of PAPR hoods results in hearing impairment comparable to moderate to severe hearing loss, and we suspect that users will experience communication difficulties as a result. Level of Evidence. Prospective study.

Powered air-purifying respirators used during the SARS-CoV-2 pandemic significantly reduce speech perception

“…In our study, the measured hearing thresholds were even 10 dB worse. The obtained mean reduction in word recognition scores of about 50% was comparable with the results reported in the study by Kempfle et al [ 16 ]. Palmiero et al [ 17 ] performed measurements of speech transmission index (STI) for different types of PPE and also reported a significantly lower (i.e.…”

“…Likewise, speech perception was significantly reduced under these conditions. This specific limitation of PAPRs has been reported previously [ 11 , 16 , 17 ] and has to be considered when this PPE is used in clinical routine. The underlying cause of these results became obvious when we characterized the acoustic properties of the PAPR.…”

“…Both factors together result in the detected restrictions in hearing and communication. Kempfle et al [ 16 ] showed a mean deterioration of hearing thresholds of about 40 dB in a different PAPR system. In our study, the measured hearing thresholds were even 10 dB worse.…”

“…In routine clinical practice, we have noticed that hearing and communication are significantly impaired when PAPRs are used. There is a small number of studies providing data which confirm this subjective impression [ 16 , 17 ]. The purpose of this study was to provide an in-depth analysis of acoustic properties of a PAPR which could potentially lead to difficulties in communication.…”

Design and development of a low-cost powered air-purifying respirator for frontline medical workers for COVID-19 response

“…Because of this reason, we eliminated design ideas that had blower fans placed directly on the head to provide direct air supply into the hood. By placing the blower on the hip using a waist bag and using a breather tube, the noise level measured inside the hood was lesser than 85 dB, as per the NIOSH recommended exposure limit for occupational noise exposure for an average of 8 hours per day [21,22]. We are continuing to improvise on the design to meet the noise level regulation of 50 dB set by the Central Pollution Control Board, India for hospitals [23].…”