Seeing Is Believing, 4 of 5

Some people, including those that have been researching the phenomenon for more than twenty years, have reported experiencing the McGurk effect even when they are aware that it is taking place. Although some people can identify most of what is being said from lip reading along, the majority of individuals are rather limited in their ability to identify speech from visual-only signals. An ability to use visual speech to increase the intelligibility of heard speech in a noisy environment can be a definite asset. Most think of speech perception as an auditory process. Studies have shown, however, that one’s use of information is immediate, automatic, and, to a large degree, unconscious^. This means that speech is not only something that is heard, it is perceived by all of the senses working together (seeing, touching, and listening to a face move). The brain is often unaware of the separate sensory contributions of what it perceives, so when it comes to recognizing speech the brain cannot differentiate whether it is seeing or hearing the incoming information.