A few factors which affect the degree of incorporating lip-read information into speech perception

The paper describes how people incorporate visual lip read information into speech perception, depending on one´s native language/culture and experience of learning a second language. Studies on lipreading show that humans can easily make a distinction between labial consonants and nonlabial ones. Then we investigated how people integrate auditory and visual speech information, by using the “McGurk effect” paradigm (H. McGurk and J. MacDonald, 1976) in which labial/nonlabial conflict is introduced. Cross language examinations were done across Japanese, American English, and Chinese. The Japanese and Chinese subjects were less susceptible to the McGurk effect than the American subjects, indicating a cultural/linguistic factor. The results for the Chinese subjects showed a correlation between the magnitude of the McGurk effect and the length of time they lived in a foreign country (Japan), suggesting a change due to second language learning