A sign language (also 'signed language') is a language which uses gestures instead of sound to convey meaning - combining handshapes, orientation and movement of the hands, arms or body, facial expressions and lip-patterns. Sign languages are usually developed in deaf communities, which include interpreters and friends and families of deaf people as well as people who are deaf or hearing-impaired themselves.
Contrary to popular belief, sign language is not universal. Wherever communities of deaf people exist, sign languages develop. As with spoken languages, these vary from region to region. They are not based on the spoken language in the country of origin (although various signed "modes" of spoken languages have been developed, such as Signed English and Walpiri Sign Language). Hundreds of deaf sign languages are in use around the world and are at the core of local Deaf cultures.
Sign languages have also arisen in hearing communities. American Indians of the Great Plains region used a sign language to communicate among tribes who used different spoken languages, and there are a few users still alive today. Other simple forms of signed communication have been developed in situations where speech is not practical or permitted, such as cloistered religious communities, scuba divers, in television recording studios, in loud workplaces, while hunting (see Kalahari bushmen) or in the game Charades.
Linguistics of sign
In linguistic terms, sign languages can be as rich and complex as any spoken languages, 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 a true language.
Sign languages are not simple pantomime, and they are not a visual rendition of a simplified version of any spoken language.
They have rich, complex grammars and, like every other language used by people, they can be used to discuss any topic, from the simple and concrete to the lofty and abstract. Sign languages, like spoken languages, organize elementary, meaningless units (phonemes in spoken languages and chiremes in sign languages) into meaningful semantic units.
Another misconception commonly held is that sign languages are dependent in some way on spoken languages, e.g. that they are merely the spelling out of the words of a spoken language using gestural symbols, or that they were invented by hearing people (many hearing teachers of deaf people's schools, for example Thomas Hopkins Gallaudet, are often stated as inventors of "Sign Language").
Fingerspelling is used in sign languages, mostly for proper names, although it is merely one tool among many. In the past, the use of fingerspelling in sign languages was taken as one of the evidences that sign languages are just broken or simplified versions of spoken languages. To say that a signed language is not a true language because it uses fingerspelling is akin to saying that English is not a true language because it contains onomatopoeic words. Fingerspelling can sometimes be a source of new signs. Signs which have evolved from fingerspelling are called lexicalized signs.
On the whole, sign languages are independent of spoken languages and they follow their own developmental paths. For example, British Sign Language and American Sign Language are different and mutually unintelligible (other than iconic signs), even though the hearing people of Britain and America share the same spoken language.
In addition, countries which have a single spoken language used throughout may have two or more signed languages being used within. Conversely, an area that contains more than one native spoken language might use the same signed language, such as the case in Canada, the United States, and Mexico; all three use American Sign Language while there are native speakers of English, French and Spanish within their borders.
Further proof of the separation of sign languages from spoken ones is the fact that sign languages exploit the unique features of the visual medium. Spoken language is aural and therefore linear. Only one sound can be made or received at a time whereas sign language is visual, hence, a whole scene can be taken in at once. Therefore, information can be loaded into many 'channels' and expressed simultaneously. As an illustration, in English, one could make the sentence, "I drove here." To add information about the drive though, one would have to make a longer sentence or even add an additional sentence. Such as, "I drove here and it was very pleasant." Or, "I drove here. It was a nice drive." However in American Sign Language, information about the pleasing nature of the drive can be conveyed simultaneously with the verb (drive) by taking advantage of the abilities of the visual mode of transmission which can take in non-manual signals (done with body posture and facial expression) at the same time as the manual sign signifying the verb, drive, is being produced. Therefore, whereas in English the sentence "I drove here and it was very pleasant" is longer than the sentence, "I drove here", in American Sign Language both sentences can be expressed in the same amount of time.
One other way sign language differs from spoken is its ability to be written. It would be a mistake however, to assume that sign languages are the only languages that have no written version. Sign languages are not often written; most deaf people who use sign language read and write the spoken language of their country. However, there have been attempts at developing systems for recording sign language. Most of these have been academic attempts at transcription, which often suffer from being unable to capture all the physical features (especially the non-manual and positional ones) used by sign language. As a result, they have not been used outside research.
The only sign language writing system which has been actually used by deaf people to write, is SignWriting, which rather than being developed by a linguist was devised by a dancer.
In principle, one could state that each spoken language has a sign language counterpart inasmuch as each linguistic population will contain deaf members who will generate a sign language.
Variations within a 'national' sign language can usually be correlated to the geographic location of (residential) schools for the deaf.
Certain sign languages are developed within a family. For instance, when parents are hearing and have no training in a sign language and a child is deaf, an informal system of signs will be developed by which they communicate. The term for these mini-languages is kitchen sign or home sign. Home Sign has also been established as a deaf child's attempt to create a language within the span of a single life time in the absence of a way to communicate, an extreme yet familiar occurence among deaf children in hearing families that use no form of signing whatsoever.
Contemporary local sign languages
- Adamorobe Sign Language (ADS)
- American Sign Language (ASL)
- Australian Sign Language (Auslan)
- Austrian Sign Language "Österreichische Gebärdensprache" (ÖGS)
- Brazilian Sign Language "Língua de Sinais Brasileira"
- British Sign Language (BSL)
- Dutch Sign Language "Nederlandse Gebarentaal" (NGT)
- Finnish Sign Language "Suomalainen viittomakieli" (FSE)
- Flemish Sign Language "Vlaamse Gebarentaal" (VGT)
- French Sign Language "Langues des Signes Français" (LSF)
- German Sign Language "Deutsche Gebärdensprache" (DGS)
- Indian Sign Language — most widely used signed language
- Italian Sign Language "Lingua dei Segni Italiana"
- Irish Sign Language (ISL)
- Japanese Sign Language "手話" (JSL)
- Malaysian Sign Language "Bahasa Isyarat Malaysia" (BIM)
- Maltese Sign Language "Lingwi tas-Sinjali Maltin" (LSM)
- Mexican Sign Language "Lengua de Señas Mexicana"
- New Zealand Sign Language (NZSL)
- Nicaraguan Sign Language "Idioma de Signos Nicaragüense" (ISN)
- Polish Sign Language "Polski Język Migowy" (PJM)
- Portuguese Sign Language "Lingua Gestual Portuguesa" (LGP)
- Quebec Sign Language "Langue des Signes Québécois" (LSQ)
- Swedish Sign Language "Tecknad svenska" (TS)
- Swiss-French Sign Language "Langage Gestuelle"
- Swiss-German Sign Language "Deutschschweizer Gebärdensprache" (DSGS)
- Taiwanese Sign Language (TSL)
Purpose-specific sign languages
- International Sign or Gestuno - constructed language
- Baby Sign - for children in the USA
- Makaton - for children and adults with learning disabilities in the United Kingdom
- Signuno - constructed language
Archaic Sign Languages
There are also a large number of less formally organised but still widely understood gesticulations and mimes.
These range from expressing universal needs such as pointing to the mouth or rubbing the stomach to indicate a desire for food, to more insulting gestures such as the one-finger salute. It should be noted that not only do these not form a coherent language but their meaning may vary between cultures.
- A High-Tech Helping Hand - Prototype Glove Translates Sign Language Into Speech
- Thomas H Gallaudet - A hearing man and a deaf university
- Ethnologue's Deaf Sign Languages Family Tree
- Dictionary of the Flemish Sign Language - Woordenboek Vlaamse Gebarentaal
- Plains Indian Sign Language