Electric cars run nearly silent, which is great for minimizing noise pollution, but bad for pedestrians who can't hear a vehicle approaching. So Audi is developing an electronic engine roar so the company's e-Tron vehicles can still be heard.
Now you might assume that Audi just stuck a few microphones around their R8 supercar and recorded its sounds as the engine was revved. But that's not the case. While they did use the sound of the gas-powered R8 as reference, for the e-Tron electric version they instead developed something Audi calls the e-Sound system.
When you hit the gas—err, accelerator—on Audi's e-Tron vehicles, a synthesized sound representing the vehicle's electric motor is generated on the fly through a series of electronics developed by the car maker. It sounds something like a mix between an electronic science-fiction soundtrack, and a full-on symphony. But most importantly, distinctly futuristic.
Instead of blasting out from under the hood, the electric vehicle's sounds come from a loudspeaker located underneath the car. And in the same way experienced gear-heads can tell one engine from another based just on how they sound, Audi hopes to create a unique signature sound for each of its electric vehicles. Now the idea of giving a unique sound to an electric vehicle is not unique to Audi, but compared to the chirp used by vehicles like the Volt to alert pedestrians, its approach will help electric cars shed their hippy-like image. [designboom]