Here's a rare treat: an audio/visual illusion!
Enable the sound on this Vine, and then watch the mouth on the left, followed by the mouth on the right:
The man appears to say either "bar" or "far" depending on which set of lips you're looking at.
Kottke.org has more info about the science behind it, called the McGurk effect.
- Read Audiovisual illusion: Bar or far? - Kottke.org
Keep this carefully in mind next time you ask a lipreader for a buck.