A child demonstrates the McGurk effect

A few years ago I made this video of my daughter demonstrating the McGurk Effect (McGurk and MacDonald 197). This effect is a demonstration of the importance of visual information during perception. Or, perhaps, it is best understood as a demonstration of the importance of listener expectations and how they can be established in real time by stunningly subtle cues.

Try opening and closing your eyes while the girl is talking. What do you hear with your eyes open? What do you hear when they’re closed?

The audio you hear is “ba ba ba”, the video you see is of the same vocal tract producing “ga ga ga”, most commonly the percept listeners experience is of a somewhat odd “da da da”.

@article{mcgurk1976hearing,
  title={Hearing lips and seeing voices},
  author={McGurk, Harry and MacDonald, John},
  year={1976},
  publisher={Nature Publishing Group}
}