Speaking with a KN95 face mask: a within-subjects study on speaker adaptation and strategies to improve intelligibility

Cognitive Research: Principles and Implications

Table 2 KN95 acoustic profile

Spectrum section	Lower frequency	Upper frequency	Intensity difference
Spectrum section	Lower frequency	Upper frequency	Mean (dB)	SD (dB)
Full spectrum	80 Hz	16 kHz	− 7.47	4.60
Low frequencies A	80 Hz	4 kHz	− 4.16	5.91
High frequencies A	4 kHz	16 kHz	− 8.56	3.45
Low frequencies B	80 Hz	2.5 kHz	− 0.36	3.35
High frequencies B	2.5 kHz	16 kHz	− 8.76	3.48
Mask resonance	178 Hz	269 Hz	+ 9.35	3.73

Average intensity difference between the mask and no mask conditions for white noise played through the mannequin speaker, calculated as mask minus no mask. Lower and upper frequency indicates the boundaries of each spectrum section