What does a car sound like?

Everyone knows that cars have engines and the fast cars have engines that roar. A car sounds like something and the best car geeks can even determine what the engine and thus what the car most likely is based on the noise it emits. Yet now with the emergence of hybrids and electric cars, the sound of the car is changing. Some parties have now started to worry about whether pedestrians are able to hear the cars anymore and if they can't that this would have implications regarding public health.

What's the solution? Well, as they did with the Chicago river, the logical answer is to reverse the flow of the river. Or in this case to make electric cars emit a sound that resembles that of an roaring internal combustion engine. Voila, problem solved!

But seriously, are the guys jumping over the problem a bit too easily? I personally have noticed that it doesn't really matter what the car actually sounds like as most of the time in urban areas where the problem is most frequent, people tend to listen to their music players with noise-canceling headphones. So the problem actually isn't solved and with the increasingly widespread adoption of portable music players, be they iPods or mobile phones, the problem is getting worse, regardless of whether the electric vehicle sounds like a "real" car or not.

Perhaps another approach could be to go back to the drawing board and think about how the fundamental problem could be changed? But then again, I don't perceive it as a problem: if I'm listening to music, I'm still paying attention to the traffic. And as an engineer the idea of making electric vehicles sound like traditional cars is very silly, in my opinion.