I have always thought that one of the neatest things about electric cars is their silent motors. Many people see that as one of their main selling points. Engineers already work hard to insulate the cabinet from as much noise as possible. Therefore, when it comes to electric cars, why would we not all embrace the sound of silence?
Public safety, it turns out, is the main reason. A vehicle with no motor noise increases the danger to other vehicles and especially to pedestrians and bicyclists. Keep in mind that this danger is largely confined to speeds less than 20 miles per hour. Beyond that speed, wind and tire noises tend to sound sufficient warning.
It appears carmakers have mixed feelings about the best approach on this matter. Why create an “engine” noise when the electric motor has none? I can understand that frustration. As the debate unfolds, various approaches are manifesting, as Dorothee Tschampa reports (“Cue the Engine Rumble” Bloomberg Businessweek, 1/13/14–1/19/14, pp. 20–21):
“BMW, maker of the i3 hatchback, and Volkswagen, maker of the tiny e-Up!, want to keep the din of electric vehicles at a minimum and will add sound only if regulations are imposed requiring them. Elon Musk, chief executive officer of Tesla Motors, said in June that electric cars should direct ‘a pleasant-sounding noise’ as a gentle warning to nearby people rather than emitting sound all the time.” (p. 20)
Why do I have a feeling we are about to enter a new age of automotive technology that has echoes of the new age of ringtones?