What sensory phenomenon does the 'McGurk Effect' illustrate regarding human speech perception?

Correct answer: Speech perception is multimodal: visual lip cues can alter or override audible sound cues

The McGurk Effect occurs when an auditory syllable (e.g., 'ba') is dubbed over a visual video of a speaker pronouncing a different syllable (e.g., 'ga'). The brain integrates these conflicting signals, causing the listener to perceive a third blend syllable (e.g., 'da'). This illusion demonstrates that human speech perception relies heavily on both visual and auditory inputs.