In-car audio is as much about relaying information to the occupants as it is about listening to music. With that in mind, one of the latest ideas to emerge from Continental is an instrument display that doubles as a sound chamber to transmit sound without the need for separate speakers.
The display is based on the company’s Ac2ated Sound technology, which it began developing a number of years ago with audio specialist Sennheiser. An exercise in system integration, the display does away with the need for separate speakers, saving cost, weight and space.
Sound is generated by actuators, which effectively turn the entire display surface into a speaker thanks to audible vibrations induced in the glass. It can transmit all kinds of sound, including speech, in “exceptional quality”.
According to Continental, a further advantage is “acoustic localisation”. As humans, we can tell where a sound is coming from and tend to turn our heads in that direction. So, when a spoken message or alert sound is produced by the display, the driver’s gaze is drawn to the instrument it’s related to, directing attention where it’s needed.
The thinking behind the combined audio and display technology comes from part of the team specialising in vehicle acoustics and also psychoacoustics, the science of how humans perceive sound.
Although the main use of the display may be to relay information and link visuals and sound more closely, Continental says the actuator technology can be integrated into almost any existing flat component in a car’s interior. By installing the actuators in door trims, headrests, A-pillars, the roof lining, and so on, there is the potential to get rid of all conventional speakers.
That could provide aesthetic benefits (no need for speaker grilles) together with a significant saving of around 40kg (about the weight of multiple speakers and fittings in a high-end audio system) and a 90 percent reduction in the space needed, which Continental estimates at 30-40 litres, depending on the number of speakers used. Some premium audio systems incorporate over 30 speakers, so the packaging benefits could be substantial too, assuming the active surface technology can match them for the audio quality.
When the original Ac2ated system was shown by Continental at CES in 2020, it was audio system-focused rather than display-focused and called the Speakerless Immersive Sound system. Then, it was integrated with Sennheiser’s Ambeo 3D audio technology. As Continental said at the time, the concept is similar to the way the wooden body of a string instrument, like a violin, acts as a resonance chamber, and the surface vibrates to project the sound. Different sizes of surfaces, such as an A-pillar compared with a door panel, handle various frequency ranges in the same way as specific types and sizes of speakers.
