I've posted this before, but I think it belongs here.

A friend of mine was performing that lysdexic tairy fale, "Rindecella", to a group of elderly people, when he noticed that a woman was standing out the front facing the audience and trying to sign the words.

She had a very puzzled look on her face as she kept looking between him and the audience. They were looking very puzzled too. It turned out that a large proportion of the people in the audience were deaf.