One - quiet environment
Two - Noisy environment
Three - mask environment
Bottom line if you’re hard of hearing on really any level (more so mid range to severe) listening to someone talking wearing a mask is a train wreck. Not only do you have the distance factor, but a lot of words coming from someone wearing a mask many times sound mumbled. Not so much to normal hearing folks, but certainly to the hearing impaired.
So you go to all the trouble and cost to find the best HA possible to communicate with others, and then find your new hearing aids really don’t work well with with people wearing masks. Who knows maybe sign language comes back in 2021 and beyond if no FDA approved vaccine is found?