You shall communicate with English - applying that rule excludes people. It is their problem. Society sets it up to eliminate them. Against the norm, it is deviance. Their behaviour is different from what the community feels is normal behaviour. Just because they are deviant from norms, that does not necessarily mean that they are doing something wrong or immoral. As an example, most, Australians can hear, and they feel that hearing is normal behaviour. Someone that does not understand, someone who is deaf, they would be considered deviant. Their action is different than what the majority finds acceptable and normal. And just like norms are relative, deviance is comparable as well. In labelling theory, being deaf is deviant if people have judged the behaviour and labelled it as abnormal. Deviance can produce more severe consequences, characterised by a severe adverse reaction that can result in even more deviant behaviour. So if society tells them that they are bad for signing instead of trying to talk, their responses could cause them to feel isolated.