Sound without exhaust: Ferrari’s new acoustic identity

Ferrari’s first electric car, the Elettrica, might not have an engine, but it does have a voice, and in typical Maranello fashion, it is designed, not simulated.

Rather than using digital soundtracks piped through speakers, Ferrari engineers created a mechanical acoustic system that amplifies the real vibrations generated by the car’s electric motors and power electronics.

A high-precision accelerometer mounted deep within the inverter casing detects these vibrations, which are transmitted through resonant structures in the body to create an audible tone.

Ferrari’s NVH and Sound Quality Manager, Antonio Palermo, says the goal from the very start was clear.

“You will not find the replica of an internal combustion engine [ICE],” he told media during a technical presentation. “We didn’t want a replica of our ICE, and we didn’t want to invent or synthesise a new sound. The puzzle was how to extract a sound from something that is silent.”

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According to Mr Palermo, the challenge was physical, not digital. In a combustion engine, sound is transmitted naturally through the exhaust and intake systems, but in an electric car, there are no moving air columns or pressure waves.

“Here we have a big chunk of stiff metal, and so the sound cannot escape,” he explained. “There is a lot of sound trapped inside, created by the e-motor and the transmission, but it cannot reach our ears.”

The solution was to treat the inverter and its casing like the body of a musical instrument.

“If sound was airborne, we could use a microphone,” Mr Palermo said. “But sound here travels in a solid, so we need a vibration sensor. That is why we used an accelerometer. It picks up the sound trapped in the metal and returns a signal we can amplify.”

Mr Palermo likened the approach to the way an electric guitar functions.

“The internal combustion engine can be thought of as an acoustic guitar,” he said. “The Elettrica is more like an electric guitar. The accelerometer is our pickup. It is not a magnetic sensor; it is a vibration sensor.”

Ferrari says the sound is authentic, belonging entirely to the components of the powertrain. Because it originates from the actual mechanical interaction between the motors, gears and structure, there is no need for pre-recorded samples or synthesised effects.