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 be difficult to understand and use. 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.

Establishing Communication

Sign language allows deaf 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 people who have hearing disabilities live normal lives. In fact, Gallaudet University in Washington, D.C., is an accredited university that is specifically geared to help deaf people learn sign language.

Child Development

According to the the National Institutes of Health, 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. Sign language allows these children to acquire language skills during this crucial period.

Different Languages

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 grammatical structure.

Hands-On Speech

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.