According to a 2005 study by Gallaudet University, two to four people out of every 1,000 in the United States are functionally deaf. Many deaf people use sign language because spoken languages can make it downright impossible to communicate in any way even if they are proficient in lip reading. Different sign languages exist around the world and are themselves cultural formations. Many deaf people in the United States and Canada use American Sign Language.
Sign language allows deaf and hard of hearing people to communicate quickly and effectively with others who use sign language, or who "sign." Most deaf people use a combination of sign language, lip-reading and written communication to go about their daily lives. Many resources have been developed in America to help deaf people who have live normal lives. Today, ASL is one of the fastest growing language being taught on college campuses.
The most important period in a child’s life for language acquisition is the first three years. After this age, as the brain matures, language acquisition becomes more difficult. Because children typically learn their native language through hearing, deaf children are at a significant disadvantage. However, sign language allows these children to acquire language skills during this crucial period. All children can get a jumpstart on acquiring communication skills by being taught sign language, which babies can understand as early as six months.
Sign language has no written component. Deaf people can only use sign language to communicate face to face. This means that the deaf must use English or another language for reading and writing, which has become increasingly important for business and communication with the advent of computers and the Internet. Thus, all deaf people are bilingual if they use sign language in addition to lip-reading. As with any second language, sign language has its own unique history, culture and grammatical structure, making the translation from signing to writing in standard English a significant challenge.
Sign language requires the use of hands to make gestures. This can be a problem for people who do not have full use of their hands. Even seemingly manageable disabilities such as Parkinson's or arthritis can be a major problem for people who must communicate using sign language. Having a broken arm or carrying a bag of groceries can, for a deaf person, limit communication. The amount of light in a room also affects the ability to communicate using sign language.