In the McGurk effect, incongruent visual information alters the auditory speech percept. We studied the strength of this effect as a function of auditory signal-to-noise ratio (SNR: -12, -6, 0, +6 dB, and noise-free) in Finnish adults, American adults and American children (8–12 years). The McGurk stimuli were A/p/V/k/ (auditory /apa/ presented with visual /aka/), A/p/V/t/, A/k/V/p/ and A/t/V/p/. As SNR decreased, proportion of responses based on the auditory component decreased and visual influence got stronger. All participants showed this pattern, though in some instances Finns showed weaker visual influence. Overall, the McGurk effect was very similar in these language and age groups.
Index Terms: McGurk effect, noise, language, age