Consumers want a quiet ride. The government and environmentalists agree that a reduction in vehicle noise is highly desirable. So why hasn’t an automaker produced a noiseless car? “Cars have to be noisy,” explained Hans Martin Gerhard of Porsche AG. Gerhard is the author of an SAE paper, “The Perfectly Silent Car—An Engineering Goal?” The paper is to be presented at the SAE World Congress in Detroit March 5-8, 2001, at Cobo Center. “Noises in the passenger compartment are necessary because they transmit messages to the driver — although some of them can be annoying,” says Gerhard. “Low interior noise levels can cause the driver to underestimate driving speed because they lose ‘acoustical contact’ with the engine.” Lack of exterior noise can also be dangerous, Gerhard continued. He says that cars would need to be silenced to solve dense automotive traffic noise, but at what risk to the elderly, children and the blind? “Customers appreciate a car for the emotions it conveys,” says Gerhard. “Since these expectations are so closely linked with acoustic properties, the answer to the completely noiseless car must be ‘no.’”