Source : Webster's Revised Unabridged Dictionary (1913)

Ventriloquism \Ven*tril"o*quism\, n. [See {Ventriloquous}.]
   The act, art, or practice of speaking in such a manner that
   the voice appears to come, not from the person speaking, but
   from some other source, as from the opposite side of the
   room, from the cellar, etc.

Source : WordNet®

ventriloquism
     n : the art of projecting your voice so that it seems to come
         from another source (as from a ventriloquist's dummy)
         [syn: {ventriloquy}]