Linguicism and sign language
Wikipedia defines linguicism as "a form of prejudice, an "-ism" along the lines of racism, ageism or sexism [or audism]. Broadly defined, it involves an individual making judgments about one's wealth, education, social status, character, and/or other traits based on choice and use of language."
Tove Skutnabb-Kangas, a renowned Danish linguist and activist in language rights against linguistic genocide in education, coined the term linguicism which defines as, in concise, a form of prejudice based on language.
Robert L. Mason. "Linguicism Toward Deaf Signers" Blog article, March 30, 2007. http://robertmason.blogspot.com/2007/03/linguicism-toward-deaf-signers.html.
ASL Rose Newsletter. Vol. 1 No 8. August 2007. http://www.aslrose.com/nlv1n8a.php
 A personal remark (2008) from Lance Cazon of Edmonton, Dene (Native Indian in the northern regions of Canada), that the priest told him in the 1970s in Northwest Territories, Canada.
You may also be be interested in phonocentrism.
audism: a discrimination based on hearing status.