Press the power button and listen to Lloyd Christmas (played by Jim Carrey) screech the most annoying sound ever known to man on and infinite loop.
Press the power button again to turn it off. Simple as that.
As the group drives down the road in a dog van Lloyd turns to Joe Mentalino (Mike Starr) and asks "Hey, you wanna hear the most annoying sound in the world?" Then screeches the sound to Joe and Harry Dunne (Jeff Daniels).
Lloyd Christmas is a loser taxi driver, who tries to return a suitcase which contains a lot of money to its owner, a beautiful woman named Mary Swanson who he took in his taxi to the airport, earlier. He must give her back the suitcase, and for that he goes with his dumb partner, Harry Dunne to a snowy town named Aspen.
But a pair of criminals who wants the money try to follow them and to steal the money in the suitcase. Moreover, Harry and Lloyd both fall in love with Mary, and they struggle each other to win her heart.
Tags: sound dumb , dumb and dumber annoying sound , dumb and dumber 1 , the most annoying sounds in the world