isnt it ridiculous all the time especially in big cities we were mad about polution and noise of the vehicles, always digged for possible ways to reduce them. To make our lives more peacful we, engineers lost our delightful sleeps, now we have the solution but funnily people are concerned about the absence of sound in it.
Well we are talking about electrical cars right, than why dont we use sound of electric its self with regards to electrics father, Mr. Tesla. Check it out http://www.youtube.com/watch?v=pJqoRaphiEk
Wow, what a great problem to have! Reduction of the noise pollution level is a great benefit and hopefully that can be maintained while providing some audible warning. Of course, if all e-cars have the same sound, then there is an additional problem since typically no two cars sound quite identical making it somewhat possible to differentiate between mutliple vehicles at different locations and moving in different directions. If all cars, or even several in close proximity, sound the same, that differentiation will become blurred and cause confusion.