The dangers of being crushed by a silent and deadly electric vehicle have been long known, but trust Audi to level its "Vorsprung durch Technik" at the issue and compose a specific "e-sound" for its cars. The handiwork of Audi engineer Rudolf Halbmeir, the new sound - which will be fitted to all Audi EVs - isn't a single monotone but created on the fly, depending on the speed of the motors, the overall vehicle speed, the current load and more.
A speaker underneath the car is responsible for warning pedestrians. "We designed it to handle as much as 40 watts, but during normal operation it ranges between five and eight watts" speaker specialist Axel Brombach says of the system. "That’s loud enough for nearby pedestrians and cyclists to hear the e-tron."
"Out of the building and to the street. A red Audi R8 e-tron pulls up around the corner, purring gently. But when Rudolf Halbmeir taps the gas pedal, the purr turns into a cultivated growl. Though not unlike an elegant V8, it is especially pure and nuanced, and is shrouded in bright and innovative overtones. The Audi R8 e-tron certainly sounds like a sports car, but also one-of-a-kind and very futuristic" Audi
Beyond 30km/h the noise of the car's own tires is apparently good enough to warn others that the vehicle is nearby, though it's unclear how artificial noise regulations still in development might impact that. No speakers are actually inside the e-tron, though some of the noise is passed through the chassis.
Although the core e-sound principle will be the same on all Audi's electric cars, the company plans to tune the system to suit the individual vehicle. So, an EV sports coupe will sound more aggressive than, say, the A3 e-tron hatchback.