Abstract
Pairing a visual stimulus with a concurrent auditory stimulus of subtly longer or shorter duration expands or contracts the duration of that visual stimulus, even when the observer is asked to ignore the irrelevant auditory component. Here we map out this relationship and find a roughly linear relationship between perceived duration of the visual component and the duration of the irrelevant auditory component. Beyond this ‘window of integration’ the obligatory combination of cues breaks down rather suddenly, at durations 0.2 log units longer or shorter than baseline. Conversely, a visual duration has virtually no effect on the perceived duration of a concurrently presented auditory duration. A model is presented based on obligatory combination of visual and auditory cues within a window defined by the respective JNDs of vision and audition.