The relationship between the visual contribution to speech perception and lipreading ability during focused and...

The study compared the lipreading ability of normal-hearing subjects during focused and divided attention and related these measures to the visual contribution to audiovisual perception. Measurement of lipreading ability during divided attention was achieved through the use of a dual-task procedure in which subjects were required to visually identify stimulus items simultaneously with the performance of an auditory processing task. The divided attention condition served to decrease lipreading performance and increase recognition variability among subjects. Lipreading ability during divided attention was more highly correlated to visual contribution magnitude, defined as the difference between audiovisual and auditory-only recognition scores, than was lipreading ability measured during focused attention. Results are related to existing models of attention which attribute dual-task decrements to processing capacity limitations.