It is imperative that we communicate, through whatever techniques available what our various forms of communication are trying to communicate. If, for example there is information conveyed by using a particular color for a particular piece of content, that fact must be communicated. Film is language. Music is language. ASL is language.
Text is language.
All of them can be semantically clarified. Braille is not a language. Media aren't languages. Although parameters of display are an integral part of presentation markup, they must not rule content. Universal Design concepts make this a central issue.