About 17 years ago, I had an accident that left me partially, and thank goodness, temporarily, deaf. During that few months, I became very good at lip reading. I no longer need to rely on it, however, years of noise have no doubt done their toll on my hearing, and like Dr. Bill says, it is much easier for me to comprehend someone when they face me, and do not have their mouth covered. Mustaches are a nuisance, just don't tell my mustachioed hubby I said that!