Which face mask is best?

How easy or difficult is it to understand someone wearing different sorts of face masks? Researchers lead by Brown determined via data collected from people with normal hearing that “cotton masks with filter inserts and masks with a transparent plastic panel were linked to/associated with the worst performance when it came to understanding what the wearer was saying. While they were surprised that listeners did not do better with transparent masks, the authors pointed out that the clear panels hurt the audibility of the speech signal more than other mask materials and that the panels often fog up, making it difficult to see the talker’s mouth.”

Masks tested included surgical masks, cloth masks with and without filters and a mask with a clear plastic insert so the speaker’s mouth could be seen.  Also, there were three possible levels of background sound: none, moderate, and high: “Once a bit of background noise was added, however, the masks started to make a difference. And, when the loudest noise was added, the differences became even clearer. When Brown spoke while wearing a surgical mask, participants could still make out over 50% of what she was saying. But when she donned the cloth mask with a filter or the transparent mask, accuracy dropped to about 30%.”

“Which Mask is Easier on the Ears?”  2021.  Press release, Washington University in St. Louis, https://source.wustl.edu/2021/12/which-mask-is-easier-on-the-ears/