For interacting with people I have come to realize that I instinctively use signals form the persons lip movement. I cannot lip read from that signal alone, but it helps me to disambiguate what one is saying if I can see their mouth move. A side effect is that if I am not wearing my glasses I will have difficulty following you.

For one on one I can manage relatively well by situating myself advantageously. But for groups, interviews and telephone calls it becomes harder. I also have to know what language you are using. If I guess that wrong, and even if you are using a language I know, I can hardly make out what you are saying. This has put me in odd circumstances: someone starts speaking to me in my native language, when I expect that person to be speaking in English. In such situations I am usually fairly lost.