I am hard of hearing as well as my father and older sister. Because we are born hearing and progressively lose our hearing we can read and speak english fine. As the hearing gets worse there is a noticeable change in voice though, pitch and volume. We've always had "family signs" and fingerspelling within our immediate family and with close family friends. 3 years ago we began taking a family class at the local library with the ASL teacher from my high school. Shortly after I began studying ASL formally in school. I completed ASL 4 this year and tomorrow will complete my independent study in ASL final. This makes me feel more secure in my loss, no matter how much of my hearing I lose I will always have ASL to rely on.
edit: I can't express how much ASL has helped communication in our family, it makes me smile just thinking about it
