To star in Dummy, Adrien Brody spent several weeks learning how to be a ventriloquist, and the training, in a sense, paid off: He gives two overly broad performances for the price of one. It's not really Brody's fault. He plays one of those only-in-the-movies losers who is such a dimly uptight, shambling putz that he's a defanged Norman Bates cartoon; no actor could have convincingly embodied him. Brody's Steven is a community-college dropout, pushing 30, who still lives at home, where he is browbeaten by his family on a daily basis. Greg Pritikin, who wrote and directed ''Dummy,'' serves up the sort of shrill ''satire'' of middle-class Jewish vulgarity in which the mere mention of words like ''brisket'' and ''klezmer'' is automatically presumed to be hilarious.
Steven decides to become a ventriloquist, a gambit that might have worked had he let out his aggression in funny and shocking ways. But even the dummy is a loser -- a wiseacre without wisecracks. Steven lands a date with his employment counselor (the appealing Vera Farmiga), and he attempts to set the mood for a romantic evening by putting on a record of...John Philip Sousa marches. If that's the sort of scene that cracks you up, then by all means see ''Dummy.''