The 2012 Audi R8 already has the looks that could pass for a stealth fighter plane, but with the incredible sound emitting from the mid-rear mounted V8 or available V10 engine, the exotic machine is on everybody’s radar. But with an electric motor, the R8 becomes much more incognito. Audi is working on just that with the futuristic R8 e-tron experimental vehicle.

With this different power source, comes a different sound in power. A throaty, high-revving exhaust note has long been recognized as something tops the automotive food chain, but when there is no internal combustion engine, that sensation disappears. That’s why Audi has developed a special sound for the Audi R8 e-tron, one that delivers a new-found sense of power with the push of its accelerator pedal. Audi has taken more than three years in developing the acoustics program for the R8 e-tron, blending the talents of composers with acoustics engineers to find that perfect sounds.  In its current form, the sound changes based on what the e-tron is doing. It comes out of a speaker blasting up to 40 watts that is attached to the bottom of the car.

The e-sound is played via a sturdy loudspeaker attached to the car’s undercarriage. Axel Brombach, the specialist in this field, shares details: “We designed it to handle as much as 40 watts, but during normal operation it ranges between five and eight watts. That’s loud enough for nearby pedestrians and cyclists to hear the e-tron.” A fraction of the sound signature enters the vehicle’s interior via airborne and structure-borne sound waves.”We could utilize sound paths and mechanical actuators for more sound in the interior,” explains Dr. Ralf Kunkel, Head of Acoustics at Audi. “After all, a vehicle body is basically a large soundboard.But we believe strongly that our e-tron models call for an atmosphere of calm, which best conveys the unique experience of electric driving.”

The e-sound for this electric-powered high-performance sports car is just the beginning. Audi notes that every e-tron model will have a sound signature all its own.