Electrifying Sound | Audi e-tron Sound System | Audi
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Electrifying sound

Electrifying sound

Audi sound engineers Rudolf Halbmeir und Stephan Gsell developed the Audi e-tron GT quattro model’s sound. We take a look behind the scenes and explore the creative process, sources of inspiration and challenges.

Copy: AUDI AG - Photo: AUDI AG Reading time: 5 min

Only consumption and emission values according to WLTP and not according to NEDC are available for the vehicle.

Soundwave e-SoundSoundwave e-Sound

Sound is an integral part of our lives and ever-present accompaniment to our daily activities. For all that, it takes many different forms—at times a gentle rustling of the wind in treetops and at others the city’s lively hustle and bustle. It could be rain drumming its own beat on a window pane or a crowd’s heady mix of furious applause and fan chants in a stadium. Sound can spark emotions and prompt memories. And it always serves as a strikingly unique identifying feature. This is especially true for our mobility solutions.

The sound of our mobility is undergoing a sea change.

As sound engineers at Audi, Rudolf Halbmeir and Stephan Gsell not only have an incredible ear but also a great deal of experience. Rudolf Halbmeir has been designing vehicle sounds for almost 20 years. With the shift to electromobility, the nature of the work here has changed. Halbmeir explains, “In my first nine years at Audi, I mainly focused on making cars with combustion engines quieter. Then my supervisor at the time asked me if I would be interested in creating sounds for electrically powered models.” Almost five years ago, Stephan Gsell joined the team. Initially, he, too, was tasked with making vehicles quieter until the first Audi hybrid model came along and changed the game.

Today, the pair are responsible for giving the Audi e-tron models their sonic signature. Doing so entails taking not only legal requirements into account, but also each car’s unique character. No easy task. As Rudolf Halbmeir says, “Meeting so many demands is a tricky balancing act. Of course, it’s important that the sound is easy on the ear. Because even the coolest options might not be a good fit with the vehicle in question.” In seeking the ideal Audi audio, inspiration can come from anywhere and everywhere.

A car’s sound is a lot like music. Along with a theme tune, it needs a kind of hook.

Rudolf Halbmeir

Audi sound engineer Rudolf HalbmeirAudi sound engineer Rudolf Halbmeir

Even everyday objects can be sources of inspiration

“A car’s sound is a lot like music. Along with a theme tune, it needs a kind of hook—a catchy, instantly recognizable melody. In my search for the Audi e-tron GT quattro model’s signature sound, I left no stone unturned, trying everything from violin through electric guitar to the Australian didgeridoo. But none of it felt right. So I started experimenting with everyday objects and finally got what I was looking for. I put a fan in front of the opening at one end of a cylindrical object and listened to what came out the other end. It was a very special, deep thrumming. I knew instantly that I had my basic note,” recalls Halbmeir.

Hitting on a basic note is a crucial first step in developing a car’s sound, but it’s not the end of the story. You also need gradations: Low frequencies evoke self-assured strength, medium ones express sportiness and agility. High frequencies, in turn, lend a certain sparkle and are a good fit with an electric car’s electro-soundscape.

Purpose-designed software for developing the Audi e-tron models’ sound.

To thrash out the finer details, the pair put their engineering skills to work in the Audi sound lab as well as with computers in the office. One of their tools is a purpose-designed program with parallels to commercial software for creating music. “When we started developing the sound for the Audi electric models, there was unfortunately no commercial software on the market that filled the bill. So instead of sitting on our hands, we programmed our own,” explains Stephan Gsell.

With the help of this technical tool, Halbmeir and Gsell kept refining the frequency structure. In the end, the result was a highly polished sample of 32 tones. They run the gamut from post-edited synthesizer sounds through noises that resemble a cordless screwdriver to recordings of a model helicopter, among others. Of course, the plastic pipe not only made it into the repertoire but is even incorporated as variations on a theme. “Thanks to the algorithm that variously mixes and weights individual tones, our sound is always being created afresh. Despite certain parallels with musical compositions, there are also differences, such as the lack of a discernible beginning, middle and end,” adds Gsell. “Instead, it’s run-on audio. The Audi e-tron GT quattro has to sound good in every driving situation. More than that, it has to be powerful and fascinating.”

Thanks to the algorithm that variously mixes and weights individual tones, our sound is always being created afresh.

Stephan Gsell

Audi sound engineer Stephan GsellAudi sound engineer Stephan Gsell

The Audi e-tron GT models’ different sound options

In accordance with statutory provisions, the Audi e-tron GT quattro comes with a compliant acoustic vehicle alert system (AVAS). In the EU and China, this is mandatory at speeds of up to 20 kilometers per hour, while in the U.S. the requirement extends up to 32 kilometers per hour. As an audible, exterior alert, this ensures that pedestrians are made aware of the approaching vehicle in urban traffic. The range of sounds that the Audi e-tron GT quattro produces, however, goes far beyond the AVAS regulations.

Exterior sound is played via a speaker at the front of the vehicle. Those who go for the optional e-tron sound package also get another speaker in the rear, plus two in the interior set into the back doors. In describing the Gran Turismo’s sound, Rudolf Halbmeir says, “We deliberately avoided imitating internal combustion engines and spaceships in sci-fi movies. Instead, the Audi e-tron GT quattro has a sporty, full-bodied rumble that oozes premium quality. All of which makes it utterly distinctive. It’s an amalgam of familiar sound patterns and new, futuristic elements.”

Control modules regulate both the interior and exterior audio, respectively. The two control units permanently remix the soundtrack to the Audi e-tron GT quattro, based on factors such as speed and accelerator pedal position. Adjustments to the driving situation are made in real time. Driving modes also play a role. Through the Audi drive select driving dynamics system, which comes as standard, the sound’s characteristics can be modulated in several stages. There are three options to choose from—efficiency, comfort and dynamic. So the driver has free rein to select the all-electric Gran Turismo’s soundtrack.

While in efficiency mode, the vehicle is limited to the AVAS warning sound. But shift to comfort mode and the rear exterior speaker comes into play, making the exterior sound even fuller. This symphony accompanies the car beyond the 200-kilometer-per-hour mark. In dynamic mode, the exterior sound is amped up and rounded out with an interior accompaniment. This means the Audi e-tron GT quattro is the brand’s first electrically driven model where individuals can choose their vehicle’s tune—whether it’s the quiet hum of the electric motor or a powerful soundscape. After all, it’s not just sound that has many facets. So do the Four Rings’ individualization options.

Components of the exterior sound Components of the exterior sound
Components of the interior soundComponents of the interior sound