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Disabilities, Opportunities, Internetworking, and Technology

Did You Know?

Less than 30% of English speech is visible on the mouth.

Even though some deaf and hard of hearing people seem proficient at speech reading, or lip reading, they are actually "guessing" more than half of the conversation. Because of the way English is produced, many of the "sounds" are hidden from view. Using prior language knowledge, context, and a technique called "closure," people who are deaf or hard of hearing can fill in the blanks and follow some conversations. Because of the importance of context, speech reading a familiar person speaking a single word, name, or place is less than 20% accurate whereas speech reading an entire sentence may be as high as 80%. Accents, facial hair, speech impairments, and poor lighting create additional problems for speech reading students.