There are laws and human rights that protect Deaf people and their (signed) languages, such as Americans with Disabilities Act of 1990 (ADA) which is a civil rights law that prohibits discrimination against Americans with disabilities (www.ada.gov), Canadians with Disabilities Act (CDA), and so on..
"Access to language is a human right." -- National Association of the Deaf, U.S.
The World Federation of the Deaf (WFD) advocates the rights of Deaf people especially in the areas of sign language, bilingual education, and accessibility including interpreting.
The United Nations protects the human rights and promotes equality of deaf people and their signed languages under the Convention on the Rights of Persons with Disabilities (CRPD) which was adopted on December 13, 2006.
Article 2 (Definition): "'Language' includes spoken and signed languages..."
Article 9 (Accessibility): "To provide forms of live assistance and intermediaries, including guides, readers and professional sign language interpreters, to facilitate accessibility to buildings and other facilities open to the public;"
Article 21 (Freedom of expression and opinion, and access to information): "States Parties shall take all appropriate measures to ensure that persons with disabilities can exercise the right to freedom of expression and opinion, including the freedom to seek, receive and impart information and ideas on an equal basis with others and through all forms of communication of their choice, as defined in article 2..."
Article 24 (Education): "States Parties shall enable persons with disabilities to learn life and social development skills to facilitate their full and equal participation in education and as members of the community. To this end, States Parties shall take appropriate measures, including: ..."
"facilitating the learning of sign language and the promotion of the linguistic identity of the Deaf community;"
Article 30 (Participation in cultural life, recreation, leisure and sport): "...persons with disabilities shall be entitled, on an equal basis with others, to recognition and support of their specific cultural and linguistic identity, including sign languages and deaf culture."
American with Disabilities Act (ADA) was signed into law on July 26, 1990 by President George H.W. The ADA is "a civil rights law that prohibits discrimination against individuals with disabilities in all areas of public life, including jobs, schools, transportation, and all public and private places that are open to the general public. The purpose of the law is to make sure that people with disabilities have the same rights and opportunities as everyone else." -- adata.org/learn-about-ada
Canadian Human Rights Commission. "Milestones of Human Rights in Canada." http://www.chrc-ccdp.gc.ca/eng/content/milestones-human-rights-canada
The section 14 of the Canadian Charter of Rights and Freedoms in Constitution Act (1982) states that:
(Interpreter) A party or witness in any proceedings who does not understand or speak the language in which the proceedings are conducted or who is deaf has the right to the assistance of an interpreter.
In the Eldridge Decision (1997), three appellants, Robin Eldridge and John and Linda Warren, all who are Deaf, were denied an interpreter service in a medical setting in British Columbia. They brought this case to the Supreme Court of Canada.
More information: "Disability and Health Care: The Eldridge Case." http://publications.gc.ca/Collection-R/LoPBdP/EB/prb012-e.htm
The European Parliament approved on a resolution on sign language and sign language interpreters on 24 November 2016.
Currently, there are about 250 deaf lawyers in the United States.
Image source: Zainab Alkebsi Mansour shared via social media.
Though there had been Deaf lawyers sworn long prior, a historic moment was that a dozen of Deaf and Hard-of-Hearing attorneys were being sworn into the Supreme Court Bar at the U.S. Supreme Court on April 19, 2016. Another best part was that Chief Justice Roberts learned how to sign "Your motion is granted" in ASL.
Eldridge Case (1997): In the Eldridge decision of 1997, the Supreme Court of Canada decided that British Columbia must provide sign language interpreters in hospitals as well as healthcare to Deaf people in order to comply with equality rights in the Canadian Charter of Rights and Freedoms.
"Convention on the Rights of Persons with Disabilities."
Itkowitz, Colby. "Supreme Court Chief Justice learned sign language to swear in deaf lawyers." The Washington Post, April 19, 2016. Retrieved, April 21, 2016: tps://www.washingtonpost.com/news/inspired-life/wp/2016/04/19/ supreme-court-chief-justice-learned-sign-language-to-swear-in-deaf-attorneys/