Deaf people use a variety of methods of communication, including sign language and speech reading (formerly known as lip reading). Many deaf people manage to communicate quite well with other deaf people and with hearing people, but some barriers to communication do exist. Speech therapists, audiologists, deaf educators and sign language instructors help people learn to overcome these barriers.
Many People Don't Sign
Many deaf people communicate with sign language, but many hearing people do not sign. Some deaf people do not sign either, but rely on speech reading and voice to communicate. Deaf people who rely on sign language for communication may find it difficult to communicate with those who do not sign.
Different Forms of Sign Language
Not all people who use sign language use the same form of sign language. In the U.S., many deaf people use American Sign Language (ASL). Some use Signed English and some use Signed Exact English. While many deaf people can communicate in all those forms, some cannot. In addition, hearing people who sign may not know all those forms of sign language. People from countries other than the U.S. use other forms of sign language, such as British Sign Language.
Difficulty Speech Reading
Not all deaf people speech read. Those who do may have difficulty in some situations; for example, when the speaker is not facing the deaf person constantly, or when the speaker has a large moustache. Speech reading involves a good bit of guesswork, because even under ideal conditions many words look alike on the lips.
Poor Literacy Skills
Deaf people sometimes communicate with hearing people by exchanging notes. Sometimes this is effective, but some deaf people have poor literacy skills. Of course, some hearing people have poor literacy skills too, but it can be a more prevalent problem for deaf people. For many deaf people, English is their second language. They learnt ASL first. ASL has its own grammar and sentence structure, and some deaf people are fluent in it but not in English.
Some deaf people also have poor vision or are blind. They cannot speech read because they cannot see a person's lips, and they cannot communicate with traditional signs since they cannot see to read signs. Deaf-blind people use a variety of communication methods, including adaptations to ASL and Signed English, tactile sign and tactile finger spelling. Many deaf people who can see and many hearing people are unfamiliar with these methods of communication, however.