Visual Speech Improves Older and Younger Adults' Response Time and Accuracy for Speech Comprehension in Noise.

Past research suggests that older adults expend more cognitive resources when processing visual speech than younger adults. If so, given resource limitations, older adults may not get as large a visual speech benefit as younger ones on a resource-demanding speech processing task. We tested this using a speech comprehension task that required attention across two talkers and a simple response (i.e., the question-and-answer task) and measured response time and accuracy. Specifically, we compared the size of visual speech benefit for older and younger adults. We also examined whether the presence of a visual distractor would reduce the visual speech benefit more for older than younger adults. Twenty-five older adults (12 females, Age = 72) and 25 younger adults (17 females, Age = 22) completed the question-and-answer task under time pressure. The task included the following conditions: auditory and visual (AV) speech; AV speech plus visual distractor; and auditory speech with static face images. Both age groups showed a visual speech benefit regardless of whether a visual distractor was also presented. Likewise, the size of the visual speech benefit did not significantly interact with age group for accuracy or the potentially more sensitive response time measure.