The human brain is an amazing thing, and apparently it tricks us at times and overrides what we hear with what we see. It’s hard to explain without seeing firsthand, but the guy in the video below is shown repeating the sound “ba”. At one point in the video, the sound remains the same but the video shows him mouthing the word “fa”. When watching him mouth “fa” but say “ba”, you actually hear the sound “fa”. If you don’t believe it, replay the clip but close your eyes and you’ll still hear “ba”. Pretty interesting and it makes me wonder if the McGurk Effect has ever been use as a defense in court.
Check out the video below to get the full effect. The narrator at times talks over the important parts of the video at times, so you may need to rewind at times.