Asahi Kasei Microdevices (AKM) has entered into a licencing agreement with the Israeli company Silentium, to use its active road noise cancellation (ARNC) system in motor vehicles. Silentium’s ‘Quiet Bubble’ software is integrated into AKM audio speech processors, and delivery of the first samples is planned for the fourth quarter of 2022.
The absence of engine noise in EVs is welcomed by many, but road noise can still intrude into the vehicle cabin – and it is often perceived as being a less pleasant noise than an engine. Thus OEMs are seeking solutions for improved NVH, and the ARNC technology reduces road noise in milliseconds, for a quieter driving experience.
The collaboration takes ARNC technology to a new level by combining AKM’s expertise in low-latency hardware components and Silentium’s expertise in noise-cancellation software. The solution offered by both companies optimises the control signal path from the reference sensors to the loudspeakers to achieve high-speed transmission of vehicle signals and low-latency algorithm processing. This is done by optimising certain components of AKM’s analog-to-digital converter (ADC) so that the measured vehicle signals are quickly routed to the company’s digital signal processor (DSP), which houses Silentium’s low-latency Quiet Bubble software.
Additional latency reductions can be achieved from the vehicle acoustics by using near-field speakers in the headrest or elsewhere in the cabin, in the immediate vicinity of the passenger’s head. Because all hardware, software and acoustic areas are made up of low-latency paths, this solution provides in-vehicle broadband noise cancellation performance that the companies say is comparable to that of premium noise-cancelling headphones.
“The switch to plug-in hybrid and battery-powered electric vehicles has a significant and lasting impact on the vehicle interior. Noises, such as those caused by tyres, come to the fore much more. The reduction of these unwanted noises is essential for a relaxed, concentrated and therefore safe driving experience,” stated Anthony Manias, head of automotive at Silentium.