Lip reading, also called speechreading, is the technique by which a person—often one who is deaf or hard of hearing—watches a speaker’s face to interpret a spoken message. Lip readers observe the movement of the lips as well as the speaker’s facial expressions and hand gestures to obtain visual clues about what is said.
Lip reading is difficult. Many sounds involve mouth movements that are invisible or barely visible. For example, people pronounce the English k and g sounds with no visible movement, and the motion associated with the t sound is only partially visible. In addition, many sounds, such as those for the letters p and b, are made with movements that appear the same. Some words, such as pot and bond, look identical to lip readers. For these reasons, most people can visually recognize only about 20 percent of the words spoken in a sentence. A speaker who mumbles or talks fast, has a speech problem, or speaks with an accent may be especially difficult to lip read.
Lip reading is much easier for a person who has some ability to hear. Audiologists and speech therapists sometimes train adults with hearing loss in lip reading to enhance their remaining hearing. Students may use lip reading in combination with a hearing aid or a cochlear implant, a device that converts sounds into electrical signals that are sent to the brain.
Early educators of the deaf taught lip reading in the 1500’s. In 1778, the German educator Samuel Heinicke helped establish lip reading as a part of the German system of teaching the deaf. In 1843, the American educator Horace Mann observed methods of lip reading used in Germany and urged that these techniques be adopted in the United States. Mann’s proposals led to the establishment of the first lip-reading school in the United States in 1867.
See also Deafness (Special language techniques) ; Sign language .
