積山薫,東倉洋一
単音節の受聴における読唇情報の役割
Abstract:The McGurk effect is a phenomenon that demonstrates a perceptual fusion
between auditory and visual(lip-read) information in speech perception
under visual-auditory discrepancy condition (using dubbed video tapes).
This paper examined the relation between the "McGurk effects" and the
intelligibility of auditory stimuli. A female narrator's speech was video
taped for ten Japanese syllables(/ba/,/pa/, /ma/, /wa/, /da/, /ta/, /na/, /ra/,
/ga/,/ka/). The video and audio signals for these ten syllables were
combined, resulting in 100 audio-visual stimuli. These stimuli were
presented to ten subjects who were required to identify the stimuli as
heard speech in both noisy and noise-free conditions. For both conditions,
the intelligibility of the auditory stimuli was measured, presenting the
auditory stimuli alone. In the noise-free condition, the McGurk effect was
small and found only in conditions in which the intelligibility of the
auditory stimuli was not 100%. In the noisy condition, the McGurk effect
was very strong and widespread. These results suggest that incomplete
intelligibility of auditory stimuli is necessary for the McGurk effect.