Article

The role of sound intensity and stop-consonant voicing on McGurk fusions and combinations

Vrije Universiteit Brussel, Bruxelles, Brussels Capital, Belgium
European Journal of Cognitive Psychology (Impact Factor: 1.09). 09/2010; October 01(4):475-491. DOI: 10.1080/09541440143000203

ABSTRACT When presented with an auditory /b/ dubbed onto a visual /g/, listeners sometimes perceive a fused phoneme like /d/ while with the reverse presentation, they experience a combination such as /bg/. This phenomenon reported by McGurk and MacDonald (1976) is here investigated in French for both voiced and voiceless stop consonants, using two levels of auditory intensity (70 dB vs 40 dB). In a first experiment, audiovisual incongruent monosyllables (A/bi/ V/gi/, A/gi/ V/bi/, A/ki/ V/pi/, A/pi/ V/ki/) uttered by a man and by a woman speaker were recorded and dubbed, using an analogical technology. In a second experiment, the same syllables articulated by the man speaker were recorded and dubbed according to digital technology. In a third experiment, the same materials as in the second experiment were used but the presentation procedure of the experimental items was changed: Audiovisual incongruent trials were mixed up with congruent ones. In the three experiments, the role of voicing and of auditory intensity were investigated. Overall, combinations were much more numerous than fusions and both types of illusions tended to increase at low intensity. Voicing had a differential effect on both types of illusions. Combinations were more numerous with voiceless consonants but fusions tended to occur more often with voiced ones. The number of illusions was affected by the dubbing technique but not by the presentation procedure.

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Cyrille Colin