Audiovisual asymmetries in speech and nonspeech

The individual contribution of the various perceptual systems to multimodal perception is typically examined by placing information from the various perceptual systems in conflict and measuring how much each contributes to the resulting perception. When one perceptual system dominates perception more than another, it is called intersensory bias. The present research examines intersensory bias using a tapping task in which participants were asked to tap to the frequency of either an auditory or visual stimulus. The stimuli that were used were either nonspeech stimuli, such as a tone and a flashing ellipse, or speech, such as a visual or auditory syllable. In past experiments that have used nonspeech stimuli, audition has been shown to dominate visual temporal perception. Based on the influence of visible speech on auditory speech perception found in the McGurk effect, it was thought that vision might influence temporal perception more when using speech stimuli than nonspeech stimuli. It was found that the ...