source: Audi AG
Since summer 2019, all newly registered electric and hybrid cars in the EU must have an artificial external sound. High time to ask the Audi sound designers how they mix the sound. Just this much: Didgeridoo sounds can be heard through the office.
Three laptops, three screens and three boxes each. Controllers, amplifiers and cables in all colors. This is what Audi sound designer Rudi Halbmeir’s desk looks like. A didgeridoo, a guitar, a violin bow and a keyboard are leaning against a shelf behind him. Are we in a recording studio? It sometimes seems like that for his employees in the open-plan office. And somehow it’s true. Because at his desk, Halbmeir mixes the sounds for the outside sound, including the Audi e-tron for China and the USA.
The highlight at the workplace: A gas pedal and a loudspeaker are hidden under his desk, with which he can accelerate a fictitious e-tron and at the same time hear the sound directly. He kicks the pedal, the sound gets louder, virtual amplitudes hit the monitors … goose bumps. For Halbmeir this is completely normal. He turns a couple of controls and clicks through the audio tracks. “We wrote the user interface ourselves. At that time, what we wanted wasn’t on the market. ”So a home-made sound studio for the workplace. After all, everyone can do off the shelf.
“Of the outside sound from Audi e-tron consists approximately out about 30th different Soundtracks, the we superimpose.” – Rudi Halbmeir, sound designer
This is how the sound of an electric car is designed
Halbmeir has been responsible for the acoustics in Audi models since 2009. The trained electrical engineer and studied mechanical engineering turned his hobby into a job. “I play seven instruments and have a recording studio at home. At the time, my supervisor thought: That might fit, ”he says with a smile.
Since then he has compiled a database of several hundred sound files and tones. “There are various synth sounds and recorded highway noise in there. I like to experiment. What a good note is: playing the guitar with the violin bow or playing the didgeridoo, ”says Halbmeir and blows a long note through his didgeridoo to prove it.
The sound reacts to the movements of the electric car
What does the perfect exterior sound for the Audi e-tron sound like? It must and should create awareness in the vicinity of the electric car. According to EU regulations, the noises must be clearly audible up to 20 km / h. In the USA they are compulsory up to 31 km / h. They signal pedestrians and cyclists that a car is approaching, accelerating or braking. “It works not only through the volume, but also through a changing sound,” explains Halbmeir. The brain quickly saves monotonous, constant tones as “normal” background noise.
Sound design up close: How does an electric car sound?
The sound should not be perceived as annoying or uncomfortable. Frequency and volume are crucial. It is crucial to mix the right tones that create a sound. “It’s almost like a symphony. The external sound from the Audi e-tron consists of over 30 different sound tracks that we superimpose. 15 of them always run in parallel. I call the type of sound realistic-technical, not too harmonious. Otherwise the sound won’t go into the subconscious, ”explains Halbmeir. When composing, he relies on his intuition: “I let the different tones guide me. I feel, I hear and I feel the music. My stomach is often more important than my ear.”
Listen up in the laboratory: the e-tron sound in the test
In the sound laboratory, Stephan Gsell and Rudi Halbmeir test the sound not only at their desk, but also on the model: an Audi e-tron technology platform. “This is very important because the speakers are different and the sounds on the car sound completely different,” explains Halbmeir. To do this, the two go to the Audi sound laboratory. “The sound laboratory is a semi-open space. This means that the room has little reflection on the ceilings and walls, but has a normal, sound-reflecting asphalt floor, ”explains Gsell. The doctor of electrical engineering has been with the acoustics team since 2015.
The laboratory looks futuristic with the foam wedges on the walls and ceiling. In the middle is an e-tron technology platform, surrounded by small microphones. The spoken word disappears almost entirely in the room. It is reminiscent of the feeling on a plane or when wearing noise-canceling headphones.
The right sound for all maneuvers of the electric car
“Who Audi moves, should also Audi Listen.” – Stephan Gsell, sound designer
Where is the external sound hidden in the e-tron? There is a small speaker in front of the right front wheel. If the car drives backwards or faster, the level increases and the noise becomes louder. The sound is dynamically adapted to the driving situation depending on the driving parameters, such as speed or load. “The noise should not only comply with the law, it should also be pleasant and simply a good sound. Anyone who drives Audi should also hear Audi, ”says sound designer Gsell.
The overall vehicle acoustics department consciously decided against the sound characteristics of a conventional combustion vehicle for the e-tron. “The e-tron should sound like an electric vehicle and not pretend a combustion engine,” says Halbmeir. Interesting: Due to different level specifications, the first Audi electric car in the EU will sound exactly like the one for China, but different from the one for the USA.
Paradox in sound design: previously quiet, now loud
Halbmeir listens to the sound of the e-tron again and says with a wink: “It’s funny: I used to have to make the car as quiet as possible. Now I have to make it louder again with artificial sounds.”