I've been lip reading for as long as I can remember...
First a basic lesson in lip reading:
It's interpreting the movements of the lips, face, tongue and sometimes throat. Because of this, many letters are mixed up because they look identical on the lips but not hearing the voiced part, such as p & b, k & g, f & v, and so on. Because of this only about 30 percent to 40 percent of words are distinguishable by sight alone.
So, three words out of a 10 word sentence, there's not much to catch is there? That's on a good day! I also use my remaining hearing to "fill in" a bit more, but not much. So you can imagine, it's pretty much a guessing game sometimes. If I know the topic, I'm able to follow along a lot easier.
Now on to a few complaints and tips from lip readers:
1. Keep stuff out of your mouth! No cigarettes, toothpicks, food, pens and pencils, etc.
2. Do not move all over, put your hands up in front of your face or turn away in the middle of a sentence.
3. Men, keep your mustache trimmed to the top of your lip. There's no way I can lip read someone like Jamie Hyneman from Mythbusters.
4. Men, if us ladies are trying to lip read you -- we are NOT flirting!! We're looking at your lips to understand what you're saying, not trying to get your number or get you in bed.
5. Do sit in a well-lit area, preferably with the lip reader's back to a light source so your face is not shadowed.
6. Don't call us liars. Just because we understood you clearly one day and the next we can't understand anything doesn't make us liars. Maybe the room's noisier, it's a difficult subject, or we're having difficulty concentrating, etc.
7. Don't over-enunciate your words. Just speak normally and clearly. It's a pet peeve of ours when people start "oooooookaaaaay caaaaannn yooooooou..." Believe me I won't give you a chance to finish that sentence.
8. Do get our attention first. A gentle tap on the shoulder, a hand wave, small stomp on the floor or flick the light a few times if we're too far away. Don't throw stuff at us, poke us hard, or the Vulcan Death Grip.
9. Don't ask us to lip read someone across the room, in a video or on TV. There's just too many variables to consider, the speakers nuances, language and accent, topic and content.
10. Do "help" our understanding by gesturing, facial expressions and the like. Just try not to mime out the whole movie you're trying to tell me about.
11. Don't test our hearing. Don't cover your mouth and say something to see if we could in fact actually hear what you're saying! That's just damn rude! (Well unless you're an Audiologist)
12. Don't assume that all deaf or hard of hearing people can lip read. Ask what their preferred method of communication is first -- an interpreter, lip reading, writing back and forth, or even cellphone messages back and forth.
13. Don't shout. It just morphs the words and doesn't make anything better.
14. Don't imitate us, make fun of us, or correct us. Just because we don't hear the right pronunciation doesn't mean you can make fun of us, start giving us speech lessons or copy our "deaf voice."
15. Do remember that lip reading takes a lot of concentration and can be very tiring and cause eye-strain and headaches for the lip reader after long periods.
So I hope this helps when you meet a lip reader!