How Lip Reading Can Affect Speech Perception

In Chapter 13 we will discuss speech perception and the methods we employ to help perceive speech. One such method that I find very interetsing is Lip reading. Lip reading, also known as lipreading or speechreading, is a technique of understanding speech by visually interpreting the movements of the lips, face and tongue with information provided by the context, language, and any residual hearing. People with normal vision, hearing and social skills unconsciously use information from the lips and face to aid aural comprehension in everyday conversation, and most fluent speakers of a language are able to speechread to some extent. Each speech sound (phoneme) has a particular facial and mouth position (viseme), although many phonemes share the same viseme and thus are impossible to distinguish from visual information alone. Thus a speechreader must use cues from the environment and a knowledge of what is likely to be said. It is much easier to speechread customary phrases such as greetings than utterances that appear in isolation and without supporting information, such as the name of a person never met before. Speechreading may be combined with Cued Speech; one of the arguments in favor of the use of cued speech is that it helps develop lip reading skills that may be useful even when cues are absent, i.e., when communicating with non-deaf, non-hard of hearing people. Lipreading is a key factor in speech perception according to the motor theory of speech perception. This theory states that people perceive spoken words by identifying the vocal tract gestures with which they are pronounced rather than by identifying the sound patterns that speech generates. I have enclosed a video clip from Scrubs showing how Lip reading can be helpful but can sometimes go wrong. Click on the title to watch the video. Enjoy!