The McGurk effect to which Sally Thomason refers,
whereby someone presented with a video of a person saying [ga] and simultaneous audio of someone saying [ba], perceives [da],
is indeed interesting, and has been exploited in various ways to get at
aspects of speech perception. You can find out more about it from
this web page at Haskins Laboratories, which includes this link to a demonstration
of the effect.
Posted by Bill Poser at March 25, 2004 12:37 PM