I remember there was a “Pimp My Ride” episode where they used a device to make a Ford Pinto sound like a Ferrari. I can’t find this device on the interwebs to save my life. I’m still looking though… I’ll comment it in if I find it.
So, if the idea to put speakers in hybrid car’s bumpers to emit sound to let pedestrians know the car is coming at them, I think that it should be a synthesizer.
As they NY Times article states, they want it to sound something like a cross between a Starship and a Formula One car… well, when I think of the sound of that, it’s the Doppler Effect I’m most reminded off… I mean, how often do you hear a formula one car where the doppler effect is not a characteristic (when the car is parked of course).
So, my thoughts are, there needs to be a controller for the car synthesizer… something akin to “rev’ing” the engine… Aha! Simple! Send a controller message from the takometer that modulates a low pass filter! I mean, not only do you want the hybrid vehicle to emit sound, you want to know if the vehicle is rapidly approaching you, or just crawling down the street. The doppler effect will always be present in anything moving towards or away from you, but it only makes sense that we perceive speed according to the pitch of the engine.
Not only will an onboard synthesizer be able to tell you that a hybrid car is around you, but it should be able to tell you how fast the car is actually going. What do you think?