Sign language

Sign languages, also known as signed languages, are special ways of communicating using hand movements and facial expressions instead of spoken words. They are full languages with their own rules and words, just like spoken languages. Each sign language is unique to a specific place and might not be understood by people from other regions, even if there are some similarities.

These languages developed in communities where deaf and hard of hearing people live, and they are very important for the culture and identity of these communities. While they are mainly used by people who cannot hear well, many hearing people also use sign language, especially those who have family members who are deaf or hard of hearing.

Sign language is different from body language, which is the way people use gestures and expressions to show feelings or thoughts without words. Experts in language study also separate sign languages from other systems, like made-up hand signs for spoken languages or simple signs used at home by families.

The exact number of sign languages in the world is not known, but each country usually has its own. Some countries even have more than one. By 2021, the most used sign language was Indo-Pakistani Sign Language, which is used by more people than many spoken languages. Some sign languages have also been officially recognized by laws in their countries.

History

Main article: History of sign language

People who could not hear have used sign languages for a very long time. An old writing from around the fifth century BC mentions sign language. It was written by Plato's Socrates. He asked how people would talk without speaking and thought they would use hand movements.

Many places made their own ways of signing. In the Middle Ages, some religious groups in Europe used hand signs. Later, explorers saw that people in Texas and northern Mexico had their own sign language.

In 1620, Juan Pablo Bonet wrote a book in Madrid about teaching people who couldn’t speak. He made one of the first systems for using hand shapes for letters and words.

Different sign languages grew in many countries. In Britain, people used hand signs for secret messages or to talk with friends who couldn’t hear. By the 1700s, a British hand sign system had formed and spread to many places, including the United States.

In the 1700s, a Frenchman named Charles-Michel de l'Épée made a hand sign system still used in France and North America. He also started the first school for deaf children in Paris. One of his students, Laurent Clerc, helped start the first school for deaf people in the United States in 1817.

Today, there is a special sign language called International Sign used at events for deaf people from many countries.

Linguistics

Sign languages are just as complex as spoken languages. Studying them as part of linguistics shows they have all the basic properties of any language. This includes duality of patterning, where smaller units combine to form larger meaningful units.

Unlike mime, signs in sign languages are set and often random, similar to most spoken languages. While iconicity (where signs look like what they mean) is more common in sign languages, it is not always the case. Sign languages organize basic units into meaningful ones, using things like handshape, location, movement, and facial expressions. Both sign and spoken languages share features such as being temporary, having clear meaning, being random, being able to create new words, and being passed down through culture.

Common features in many sign languages include special ways to show changes and syntax. Sign languages can show meaning at the same time using space, two hands, and facial expressions. Today, linguists study sign languages as real languages.

Relationships with spoken languages

Many people think sign languages are just spoken languages shown with signs or made up by hearing people. But sign languages grow naturally in deaf communities. As they grow, sign languages sometimes use parts of spoken languages, like a manual alphabet (fingerspelling) for names or ideas that do not have signs yet. But sign languages are separate and follow their own paths. For example, British Sign Language and American Sign Language are quite different, even though people in the UK and the US share the same spoken language.

Spatial grammar and simultaneity

Sign languages use the visual world to their advantage, sometimes using space to show a thing's type, size, shape, movement, or distance. While sign languages can show meaning at the same time, this is limited by how fast people can move and often follows a line.

Non-manual elements

Sign languages use facial expressions and body movements to show things like feelings, differences between similar signs, grammar, and discourse ideas. For example, facial expressions can tell the difference between signs that look similar with the hands.

Iconicity

Iconicity, where the shape of a sign relates to its meaning, is studied in sign languages. While early linguists thought it was not important, it is now seen as a feature that changes among sign languages. Iconicity can help with learning and remembering but does not make a language valid.

Classification

Sign languages can be grouped based on how they start. Home sign is informal and used by one person, while village sign languages are shared in places with many deaf people. Deaf-community sign languages grow where deaf people make their own communities. Speech-taboo languages are gestures used by hearing people, sometimes taken up by the deaf.

Typology

Sign languages differ in word order and often use incorporating classifier languages. They also have different ways to show numbers.

Acquisition

Children who learn sign language from birth pick it up naturally, just like hearing children learning spoken language. Studies show that children who grow up with sign language do better in some tasks and have differences in grammar.

Written forms

Sign languages do not have a traditional written form, but some systems have been made to write them down, including Stokoe notation, Hamburg Notation System, SignWriting, and others. But there is no agreed-upon written form that everyone uses.

Sign perception

People who use sign language from birth see and sort out handshapes and other parts based on what they see, which affects how they use and make signs.

In society

Deaf communities and Deaf culture

Main article: Deaf culture

When there are only a few deaf people in a place, they often form their own special group. These groups exist all over the world, especially in cities and countries, and they have their own rich cultures.

One special kind of sign language is Black ASL. It was created in schools for black deaf students during a time when schools were separated by race.

Use of sign languages in hearing communities

Sometimes, in places where many people are deaf, the whole community uses a special sign language. This can happen in small villages. Famous examples include:

• Martha's Vineyard Sign Language, United States
• Al-Sayyid Bedouin Sign Language, Israel
• Kata Kolok, Bali
• Adamorobe Sign Language, Ghana
• Yucatec Maya Sign Language, Mexico

In these places, deaf people are usually accepted and treated the same as everyone else.

Many Australian Aboriginal sign languages developed because of special rules about speaking in certain situations, like during sad times or special ceremonies. They were especially well developed among the Warlpiri, Warumungu, Dieri, Kaytetye, Arrernte, and Warlmanpa.

A sign language also developed among tribes of American Indians in the Great Plains of North America before Europeans arrived. It was used to help different tribes talk to each other, and some people still use it today among the Crow, Cheyenne, and Arapaho.

Sign language is also used by people who can hear but have trouble speaking.

Schools and colleges are more interested in teaching sign language. In the U.S., many students are choosing to learn American Sign Language as a second language. In New Zealand, after a law was passed in 2006, schools started offering New Zealand Sign Language as a subject for students.

Legal recognition

Main article: Legal recognition of sign languages

Some sign languages have laws that support their use, while others do not. People believe that sign languages should be recognized and supported, not just as a help for people who are deaf, but as the way that whole communities communicate.

Laws about showing sign language on TV and in other places are different in each country. In the United Kingdom, rules were made in 1996 and updated in 2003 to help make sure deaf and blind people could watch TV.

Interpretation

Main article: Language interpretation § Sign language

To help deaf and hearing people talk to each other, sign language interpreters are often used. This needs a lot of work because sign languages have their own special ways of expressing ideas, just like spoken languages.

Interpreters usually change words from one sign language to one spoken language used in the same country, like French Sign Language to spoken French in France, or American Sign Language to spoken English in the U.S. Interpreters who can change words between languages that are not usually paired, like Spanish Sign Language and English, are also available but less common.

Sign language is sometimes shown on TV programs that have talking. The signer usually appears in a corner of the screen, and the show might be smaller so both the signer and the program can be seen. Live sign language interpretation for big events like press conferences is becoming more common.

Technology

One of the first times technology helped deaf people talk to each other was in 1964 at the New York World's Fair, when two deaf people used a special phone to talk. But video calling did not become common until the early 2000s when the Internet had enough speed.

Now, deaf people can talk using video calls, either with special devices made for sign language or with regular video calling services on computers. Some special devices can help make the signing clearer.

Main articles: Video remote interpreting and Video relay service

With new technology, interpreters can be in different places. In video remote interpreting, the interpreter is in one place and talks to a deaf person and a hearing person who are together somewhere else. Video relay service lets a deaf person, an interpreter, and a hearing person all talk to each other even if they are in three different places.

New computer programs are being made that can change videos of sign language into written words.

Sign language is also used in movies. In Brazil, all movies shown in theaters must have a special track in Brazilian Sign Language that can be played on a second screen.

Sign Union flag

The Sign Union flag was designed by Arnaud Balard. It shows the shape of a hand and uses three colors: dark blue for deaf people and humanity, turquoise for sign language, and yellow for hope. The flag is meant to be a welcome symbol for deaf people all over the world.

Language endangerment and extinction

Just like spoken languages, sign languages can also disappear. For example, a sign language used by a small group might be replaced by one used by a larger group. This has almost happened to Hawai'i Sign Language, which is only used by a few older people now. Even well-known sign languages can lose users. Ways are being found to measure how healthy a sign language is.

Extinct sign languages

• Angami Naga Sign Language
• Henniker Sign Language
• Martha's Vineyard Sign Language (MVSL)
• Old French Sign Language (VLSF)
• Old Kentish Sign Language (OKSL)
• Pitta Pitta sign language
• Plateau Sign Language
• Rennellese Sign Language (RSL)
• Sandy River Valley Sign Language
• Warluwarra sign language

Communication systems similar to sign language

Main article: Manually coded language

Some communication systems look like sign languages but are not full sign languages. These systems develop when people who can hear and people who are Deaf try to talk to each other. They might use signs from a real sign language but follow the rules of spoken language. These systems are usually only used to help teach Deaf children how to speak and are not used outside of school.

Main article: Baby sign language

Some parents who can hear teach signs to their young children. This helps because babies' hands grow faster than their mouths, so they can use signs before they can talk. This makes it easier for parents to understand what their baby wants. When the child starts talking, they usually stop using signs. This is different from children who grow up with Deaf parents, who often learn a full sign language.

Main article: Home sign

Sometimes, families create their own simple sign systems. For example, if a family has a child who is Deaf and the parents do not know sign language, the child might naturally create signs to communicate. These signs help the child share ideas but are not a full language. They are not as complete as real sign languages.

Main article: Great ape language § Primate use of sign language

Scientists have taught some animals, like chimpanzees, gorillas, and orangutans, to use signs to talk with humans. However, this does not mean the animals know a full human language. They only learn some signs or words.

Main article: Origin of language § Gestural theory