Lip Reading

Speechreading supplements but rarely replaces hearing

Overview

Lip reading, more broadly called speechreading, is understanding speech by watching the movements of the lips, face, and tongue together with expressions and gestures. Only a limited portion of spoken English can be identified from the face alone, because many sounds, such as k, g, and h, are produced out of sight, and groups of sounds called visemes, such as p, b, and m, look identical. Speechreaders therefore rely heavily on context, prediction, and any residual hearing, which makes it cognitively demanding and tiring. Ease of speechreading depends on lighting on the talker face, a clear view, natural rhythm, and absence of exaggerated or shouted speech, which distorts mouth shapes. Even listeners with normal hearing use visual cues, as shown by the McGurk effect, in which seeing one syllable while hearing another changes what is perceived. Speechreading classes are offered in some countries, and it remains an important part of daily communication for many people with hearing loss.