Time-compressed visual speech and age: A first report

Objective: The purpose of this research was to investigate the effects of age on the ability to identify temporally altered visual speech signals. Design: Two groups of adult lipreaders, older (N = 20) and younger (N = 15), were tested on perception of visual-only speech signals. Identification performance was measured for time-compressed, time-expanded, and unaltered versions of words with visual only speech. Results: An overall reduction in lipreading ability was observed as a function of age. However, in contrast to results with time-altered auditory speech, older adults did not show a disproportionate change to speeded or slowed visual speech. Conclusions: The absence of age effects in the identification of temporally altered visual speech signals stands in contrast to the considerable evidence that older adults are disproportionately affected by temporal alterations of auditory speech signals. These results argue against a generalized slowing of information processing in older adults and instead point to modality specific changes in temporal processing abilities.