Fig. 3

Impact of the powered air-purifying respirator (PAPR) on hearing performance in normal-hearing subjects (n = 10). A Boxplots of hearing thresholds (dB HL) with PAPR (white), without PAPR (grey) and with PAPR + headset (plaid) using tone audiometry. The vertical bar (***) applies for “without PAPR” vs. “with PAPR” and for “without PAPR” vs. “with PAPR and headset”. B Boxplots of speech recognition scores (%) for numbers and monosyllabic words (Freiburg speech test) without PAPR (black), with PAPR (grey) and with PAPR + headset (white) at 65 dB. C Boxplots of speech reception thresholds (SRTs) in dB SPL with PAPR (straight striped), without PAPR (white) and with PAPR and headset (plaid) as well as with attenuation of PAPR (oblique plaid), with attenuation of a surgical face mask (oblique striped) and with attenuation of an FFP3 respirator (grey) obtained with the German matrix test. Box plots show minima, maxima, interquartile range and median. Significant differences not indicated in the graph: without PAPR vs. with PAPR, without PAPR vs. with PAPR and headset, without PAPR vs. S: PAPR / L: PAPR, S: SFM / L: SFM vs. with PAPR, S: SFM / L: SFM vs. with PAPR and headset, S: SFM / L: SFM vs. S: PAPR / L: PAPR, S: FFP3 / L: FFP3 vs. with PAPR, S: FFP3 / L: FFP3 vs. with PAPR and headset, S: FFP3 / L: FFP3 vs. S: PAPR / L: PAPR (p < 0.001, respectively). S = speaker, L = listener, SFM = surgical face mask, FFP3 = FFP3 respirator. *p < 0.05; ***p < 0.001