For people who spend a lot of time on the road, their vehicle is like a haven or a second home, and good sound is an important part of it. For some time now, many car audio systems have been overtaking home systems. And there’s also much more they can do, for example, by improving road safety and helping navigation.
In the car world, slowly but surely, modern audio systems are taking the driver’s seat. But many cars are still lugging around heavy sound systems and subwoofers. Radio, loudspeakers and cables alone in a normal vehicle can weigh up to 40 kilograms – impacting fuel consumption and thus also the environment. For this reason, Continental has embarked on a new, forward-looking path and developed a speakerless technology: The Ac2ated Sound System produces sound by making existing surfaces in the vehicle vibrate using specially developed actuators.
Dimitrios Patsouras, Head of Competence Center NVH (noise, vibration, harshness), explains the concept: “We approach the entire car like a sound box, in the same way as a classical string instrument whose wooden body acts as a resonance chamber. Each part of the car – the body panels, door trim, roof trim, trunk – has certain acoustic characteristics of its own. We have tried to turn this to our purposes and asked the question, are speakers still necessary if the car itself has the prerequisite for generating sound? The answer was not really, and so the idea for the Ac2ated Sound System was created. The point is to treat the car like an orchestra. The column panels are the violins, the door trims are the cello, while other parts of the vehicle are the double bass. The real trigger for the idea, however, was not the issue of sound as such, but of identifying potential savings in vehicle weight.”
Not only is this good for the environment, it also delights carmakers and designers because no wide loudspeaker fronts need to be planned and integrated. Compared with conventional sound systems, this means a reduction in weight and space of 75 to 90 percent. Electric vehicles in particular, in which weight and space are paramount, would benefit from the new technology.
Tuning the instrument: The frequency characteristics of the individual resonating bodies in the vehicle will later produce an unmistakable orchestral sound.
No good sound without a team – vehicle acoustics specialists, sound designer, psycho-acoustics and mechanical engineers of the NVH (Noise, Vibration, Harshness) Competence Center.
It has to vibrate: In the plate test bench, the materials used in the vehicle are tested for their vibration behavior together with the actuators.
Johannes Kerkmann, psycho-acoustics engineer and guitarist, finds the right sound everywhere – including on the liftgate.
We have developed a premium sound system that reduces both space and weight. At Continental, we call this harmonious sustainability.
But that’s not all: In the future, vehicle occupants will be able to relax and enjoy breathtaking sound experiences, while driving will become almost a secondary issue. In collaboration with the audio pioneer Sennheiser, Continental can provide 360-degree in-car sound. This is made possible by the AMBEO Mobility Software Technology from Sennheiser, whose integrated algorithm automatically converts stereo sources into 3D sound, without the need for a specific 3D audio source. The result is an immersive sound experience that puts the occupants in completely new, lifelike acoustic surroundings, giving them the feeling that they are in a concert hall immersed in the music.
However, a unique musical experience is only one aspect of modern car audio systems. Modern cars emit a wide range of other sounds – clicking turn signals, parking assist, navigation assist, warnings, incoming messages, phone calls. Although they each have an important function, they usually have to be controlled separately from one another. For drivers, this can be not only nerve-wracking, but also a safety risk. “That’s why we’re introducing fundamental changes to the in-car sound environment,” says Dimitrios Patsouras. “For example, combining noise reduction with infotainment, like with noise-reducing headphones, which can do much more than just reproduce music. Relevant noises from the car, navigation system announcements or other audio information are recorded in a way that delivers optimal driver comprehension and reduces other noise inside and outside the vehicle.”
Centralized audio management integrates all sound sources in the vehicle into a single system. It can also prioritize, individualize and target sounds in order to draw the driver’s attention to points on the road that are important for safety. For example, a vehicle approaching from the right would generate an audible warning signal in the car on the right-hand side, while covering up all other sounds. In addition, the sounds can be designed so that an audible alert is more intense when a pedestrian is crossing behind the vehicle than when the driver is driving towards a bollard.
Sonification: Turning Data into Sounds
By converting data such as traffic data or advanced driver assistance system data into sound (“sonification”), driving can be made safer or relieve stress in stressful situations: For example, as the car approaches a turn, the tone becomes faster – thus saving the driver the trouble of estimating the distance or relying on the distance shown on the display panel. Turning corners will also be made easier by a turning sound generated from the direction in which the car is to be steered. This will allow the driver to focus on the road – a tangible safety gain in stressful driving situations, such as in urban traffic or in an unfamiliar area.
For safe overtaking, the turn signal tone can simultaneously act as a blind-spot assistant: when the driver puts on the turn signal, the tone is overlaid with an audible warning. The turn signal only returns to normal when the lane is free, allowing the driver to change lanes after checking over their shoulder. This means that drivers won’t have to spend a long time looking for a gap in the passing traffic and will be able to focus more of their attention on the vehicle in front. The collision warning system will work in a similar way: An audible alert will warn the driver of approaching vehicles, even if they are still around a bend.
Outside the vehicle, too, audio will take on a new dimension, as Dimitrios Patsouras explains with regard to electric mobility: “The first legislation has come out, for example, in the USA and the EU, requiring electrically powered vehicles have to be fitted with an Acoustic Vehicle Alerting System (AVAS). When implemented, these specifications will require vehicles running in electric mode at speeds below 30 km/h to emit more noise than well-tuned vehicles with combustion engines. As a result, a multi-story car park will become a concert of cacophony. Of course, local residents won’t be happy if vehicles make even more noise despite being electric. However, there is a technical solution: Sensors on the vehicle could assess whether the artificial vehicle noise is necessary in the first place. It will only be activated if necessary.”
Sounds to the Driver’s Taste
Apart from the numerous safety features, central audio management also has plenty of room for individualizing the sound experience. For example, personal sounds can be set for non-safety-critical functions, be it a birdsong, parts of your favorite track or sounds from science fiction blockbusters. Third-party sound algorithms can also be integrated, for example, for noise reduction or for the 3D sound described earlier.
Talk to Me – the Continental Smart Voice Assistant
If we add the potential of language assistants, driving becomes even more comfortable and safer. The Continental Smart Voice Assistant significantly reduces distraction when driving as it does away with the need for touchscreens or buttons for frequently used functions. Instead, drivers can activate the intelligent voice control system using individual speech recognition, as is familiar on smartphones, and then, for example, communicate their music requests or destination using a voice command. Even more basic vehicle functions can be controlled in this way. For example, the assistant can explain the warning symbols on the display board and provide a recommendation for the driver as soon as the Smart Voice Assistant is called up. In addition, the system learns from the driver’s behavior and preferences and can therefore adapt and improve courses of action.
A. „Hey Siri!“
Language Assistants in the Home
Whether it’s Amazon’s Alexa, Google Assistant or Apple’s Siri – modern voice assistants have long since broken free from the smartphone and have now taken up residence throughout the home. A voice command is enough for you to hear the music you want. In the same way, you can ask for the news, sports results and the weather report, or control the volume, light and even the heating in a “smart home.” The possibilities are endless – as long as there are words for it.
B. If you’ve heard this track, you may also like...
Automated listening recommendations
It used to be that people were limited by their record collections. Today, users can access unlimited online music through streaming services. Spotify alone has 40 million tracks on offer. If the choice is simply too much, you can rely on recommendations generated by artificial intelligence and big data. The software learns your taste in music. It recognizes whether you listen to a song all the way through, sorts the music by rhythm and mood, and can even tell if you were at home, on the way to work or at the gym while you were listening.
C. Artificial Vrooms:
Sound Designs for Electric Cars
Electric cars are so quiet that they’re barely audible, but this poses a safety risk for pedestrians and cyclists. According to an EU regulation, Acoustic Vehicle Alerting Systems (AVAS) will be mandatory for all electric vehicles from 2021. The sound must resemble an internal combustion engine, reach a certain volume and vary as the vehicle accelerates or decelerates. Otherwise, the sound creators are free to create any artificial engine sound they want. Carmakers have got really creative: BMW, for example, has hired the Hollywood film composer Hans Zimmer.
Wireless Headphones and Speakers
The days of cable clutter are gone. Today’s headphones and loudspeakers are wireless, connecting with the source of the sound – a smartphone or tablet – via Bluetooth. Voice assistance also allows you to control the music or volume hands-free. And if that’s not enough, you can set up speakers across your home, connect them to the local WiFi and your multiroom sound system is ready to enjoy. It doesn’t get more convenient than that!
E. The “Toniebox”:
With Continental in the Kids’ Playroom
With millions sold in Germany, Toniebox is a digital player for kids’ audio stories, for which Continental supplies the casing. The skai Evida Venezia material is soft but robust and water-repellent. More than 80 percent of the casing is made of natural or renewable raw materials. This makes the audio boxes a perfect companion for kids who love listening to audio stories. So it comes as no surprise that the product won the Red Dot Award: Product Design 2016 Best of the Best.
The cars of the future may come without conventional loudspeakers, but they will have unprecedented sound systems. Simultaneously, modern audio systems are utilizing all available options to further increase vehicle safety. Continental is driving this development with innovative solutions and is therefore well positioned for the future – both audio and automotive.