3 ms·
I'm pretty sure the difference they're referring to is already there in the raw results - remember, they're measuring how well the masks protect others against
by makomk 6y ago
I'm pretty sure the difference they're referring to is already there in the raw results - remember, they're measuring how well the masks protect others against the wearer by filtering out expelled moisture droplets, and the results show that valved N95 masks are worse than non-valved (though about as good as the very best of the cotton masks).
- yyyk 6y agoI doubt the results completely account for the airflow effect, and perhaps the researchers were careful enough to note this. After all, they merely tested one infected person speaking at whatever level is normal for that person at that stage of the disease. It's quite possible that the typical carrier has stronger flow. Besides, sometimes people yell - quite a few people have reason to be on edge these days.
- davidgould 6y agoThey did not test an infected person. They measured droplets, not virus. Disease progress is not relevant to this paper.
- yyyk 6y agoOuch. I read droplets and thought 'virus'. That said, my point about the speaker not being representative is still correct. We have no idea if the speaker's speech is typical. It could be their flow is lower than the average.
- davidgould 6y agoThey tested with four speakers and ran additional tests with one speaker. Results are consistent across the speakers. Consider also that they are measuring the relative filtration of different masks, not the absolute filtration.