SCOTT SIMON, HOST:

New rules made final this month will require electric and hybrid cars to be noisier. Many people just can't hear them coming. The National Highway Traffic Safety Administration says the new standards could prevent 2,400 injuries a year. NPR listeners were once invited to tell us what they'd like to hear coming out of electric cars. The clear winner...

(SOUNDBITE OF HOVER CAR)

SIMON: ...The hover car from the Jetsons. So can we have that?

ROBERT STRASSBURGER: Unfortunately, under the rule, no.

SIMON: Robert Strassburger, vice president for vehicle safety at the Alliance of Automobile Manufacturers.

STRASSBURGER: The sound to be emitted really has to be instantly recognizable as a motor vehicle in operation.

SIMON: Mr. Strassburger worked with the National Federation of the Blind to develop the rules. At first, he says, he told them, but we've worked for 30 years to make cars quiet.

STRASSBURGER: One of the gentlemen from the NFB with whom we worked actually was hit by a hybrid vehicle. He did not hear it. And so it's, I think, critically important that the sound emitted does sound like a car. It benefits all of us - but, most particularly, the blind.

SIMON: Auto manufacturers need to make their new cars noisier by September 2019. What about a little theme music?

(SOUNDBITE OF HERB ALPERT AND THE TIJUANA BRASS COMPOSITION, "TIJUANA TAXI") Transcript provided by NPR, Copyright NPR.