Diao, Yali; Chandler, Paul A.; and Sweller, John, 2007, The effect of written text on comprehension of spoken English as a foreign language, American Journal of Psychology, 120(2), 237-261.
Based on cognitive load theory, this study investigated the effect of simultaneous written presentations on comprehension of spoken English as a foreign language. Learners' language comprehension was compared while they used 3 instructional formats: listening with auditory materials only, listening with a full, written script, and listening with simultaneous subtitled text. Listening with the presence of a script and subtitles led to better understanding of the scripted and subtitled passage but poorer performance on a subsequent auditory passage than listening with the auditory materials only. These findings indicated that where the intention was learning to listen, the use of a full script or subtitles had detrimental effects on the construction and automation of listening comprehension schemas.