Over 37 million adults and over 1 million children in the United States have some degree of hearing loss. In the U.K. around 840 babies are born with significant deafness each year. About one in 1,000 children is deaf at three years old and about 20,000 children aged up to 15 are moderately to profoundly deaf.
A sign language (signed language, or simply signing) is defined as a language which uses manual communication and body language to convey meaning, as opposed to acoustically conveyed sound patterns. This can involve simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's thoughts. They share many similarities with spoken languages (sometimes called "oral languages", which depend primarily on sound), which is why linguists consider both to be natural languages, but there are also some significant differences between signed and spoken languages.
Sign languages commonly develop in deaf communities, which can include interpreters and friends and families of deaf people as well as people who are deaf or hard of hearing themselves. Research shows that babies are not born with a blank slate of their brains when it comes to language. Sign language enables infants to speak earlier than speech language in the early stage of physical development. Next generations might be able to speak both vocally and manually.
In linguistic terms, sign languages are as rich and complex as any oral language, despite the common misconception that they are not "real languages". Professional linguists have studied many sign languages and found them to have every linguistic component required to be classed as true languages.
Sign systems are sometimes developed within a single family. For instance, when hearing parents with no sign language skills have a deaf child, an informal system of signs will naturally develop, unless repressed by the parents. The term for these mini-languages is home sign (sometimes home-sign or kitchen sign).
British Sign Language and American Sign Language are quite different. On occasion, where the prevalence of deaf people is high enough, a deaf sign language has been taken up by an entire local community. Famous examples of this include Martha's Vineyard Sign Language in the USA, Kata Kolok in a village in Bali, Adamorobe Sign Language in Ghana and Yucatec Maya sign language in Mexico.
The language of which British Sign Language (BSL), Auslan and New Zealand Sign Language (NZSL) may be considered dialects. These three languages may technically be considered dialects of a single language (BANZSL) due to their use of the same grammar, manual alphabet, and the high degree of lexical sharing (overlap of signs).
The sign language of the Australian deaf community. The term Auslan is a portmanteau of "Australian sign language", coined by Trevor Johnston in the early 1980s, although the language itself is much older. Auslan is related to British Sign Language (BSL) and New Zealand Sign Language (NZSL); the three have descended from the same parent language, and together comprise the BANZSL language family.
The main language of the Deaf community in New Zealand. It became an official language of New Zealand in April 2006, alongside Maori and English. Like other natural sign languages, it was devised by and for Deaf people, with no linguistic connection to a spoken or written language, and it is fully capable of expressing anything a fluent signer wants to say.
The preferred signing system for hearing people to communicate with the deaf. It uses the same signs as BSL, but unlike SE, you do not have to sign every word. It also doesn't have its own grammar system like BSL, so hearing people do not have to worry about learning a whole new grammatical structure. This can be picked up fairly quickly to expedite communication.
A signing system as well. It has one sign to represent each word in the English language, but is not a language like BSL. It is intended to be used to help with reading and writing, and has important signs to teach grammar.
Also known as IS, is an international auxiliary language used at international meetings such as the World Federation of the Deaf (WFD) Congress and events such as the Deaflympics.
A signing system used with speech to help those with language difficulties. There are 37 basic signs which when combined can make over 4000 more complex ones.
A very crude signing system. It combines elements of BSL and spoken English to allow communication between hearing people and deaf who only know the strict confines of sign language. It is not recommended but can be used when needed.
A complete, complex language that employs signs made with the hands and other movements, including facial expressions and postures of the body. It is the first language of many deaf North Americans, and one of several communication options available to deaf people. ASL is said to be the fourth most commonly used language in the United States. American Sign Language is the dominant sign language of the Deaf community in the United States, in the English-speaking parts of Canada, and in parts of Mexico. Although the United Kingdom and the United States share English as a spoken and written language, British Sign Language (BSL) is quite different from ASL, and the two sign languages are not mutually intelligible.
The sign language used in the United Kingdom (UK), and is the first or preferred language of deaf people in the UK; the number of signers has been put at 30,000 to 70,000. The language makes use of space and involves movement of the hands, body, face and head. Many thousands of people who are not Deaf also use BSL, as hearing relatives of Deaf people, sign language interpreters or as a result of other contact with the British Deaf community.
Widely used in Mexico city, Monterrey and in Guadalajara.It varies even within a country. In Mexico, most people use the Mexican sign language. It is also known as "lengua de seaas mexicana", "Lenguaje de Signos Mexicano" or simply LSM. It is mainly used in the urban region by about 87000 people.
A signing system generally used alongside sign language. It is used to spell out names, places, and anything else there is not a sign for. Many times new words take longer to spell out into BSL so must be spelled before a sign is adopted. BSL finger spelling is also different from ASL, as it uses two hands whereas ASL uses one. BSL is also distinct from Irish Sign Language (ISL) (ISG in the ISO system) which is more closely related to French Sign Language (LSF) and ASL.