Selling silence -Transforming the cabin into a quiet bubble
By Matthew Beecham, 23 March 2021- JUST AUTO
Could you tell us a little more about Silentium?
Silentium creates personal in-car sound environments through patented Active Acoustics technology new to the car industry. We’re based just 30 minutes outside of Tel Aviv, Israel. We also have people positioned strategically around the world – I’m based in Kent, UK, for example. The company started around 14 years ago with an R&D team specialising in acoustics and electronics. Our motto was: “providing peace and quiet to the world”, with a mission to cut out distraction in everyday life, across the office and home, in hospitals and hotels, and in cars, trains and planes. Today, we are mainly focused on automotive, with our team of 60 NVH and electronics specialists developing our proprietary broad-band road noise cancellation technology.
Active noise cancellation systems are becoming commonplace on premium cars. Who are your customers and what is your USP?
JLR was the fastest OEM to bring Silentium’s Active Acoustics software to market in October 2020. Our USP is that we can cut out 90% of unwanted noise across a broader band of frequencies than any other technology on the market – from 20Hz up to 1kHz – and help prevent driver fatigue on longer journeys.
Like many new technologies, our Active Acoustics system featured on premium cars to start. But the principle we use for high-end vehicles with premium sound systems is quickly being adapted for smaller, lower-cost vehicles in the lower car segments, just like ABS and HVAC systems were developed in the past for the luxury car segment and then filtered to lower segments.
Almost every car on sale today has a decent speaker system. While premium cars usually have better audio that will cover more frequencies, as long as there are speakers and we can put sensors in the right locations on the vehicle, Active Acoustics will work. We hope that Silentium solutions will become commonplace across a wide range of car classes for all drivers.
Beyond eliminating road noise, how can your solution help to take out unwanted noises or add desirable noises?
Silentium’s Active Acoustics technology can reduce, cancel or enhance sound inside any vehicle. The Active Road Noise Cancellation (ARNC) technology in JLR vehicles, for example, lowers unwanted noise peaks by 10dB and overall noise levels by 3-4dB – the equivalent of reducing the volume of the car’s sound system by four levels.
The technology also reacts to increase the noises you want to pay more attention to, such as telephony or alerts from the car, and is configured to let ambulance and siren noise be unaffected. This is enabled by the development in processing power, which allows monitoring and adapting through the hardware and software in real time.
Removing unwanted noise and creating a more pleasant acoustic environment is emerging as a point of brand differentiation. Can all cabin sounds, including voice, be controlled?
The technology is definitely there. We have created the Quiet Bubble™, formed through Silentium’s software working with additional sensors and microphones to create a quieter and more refined sound profile for occupants in a vehicle. Our Quiet Bubble can create a space around 1ft in diameter around each occupant’s head, which allows the driver or passengers to experience a quieter environment in their seat specifically.
The ability to integrate this into our Personal Sound Bubble technology means passengers can listen to their own music, without it interfering with other occupants’ audio experience. For example, the driver can be listening to navigation instructions while the passenger listens to their own music or a podcast.
Being able to combine personalised audio with active road noise cancellation to create fully separate sound environments for passengers is approximately 2-3 years away; we are actively developing this technology now.
Increasing levels of electrification mean noises from the road or wind are more pronounced. How are you addressing that?
In an ICE car, you can predict the noise and the frequencies of the engine, based on inputs such as RPM, which makes it easier to cancel them out. In an EV, the focus is more on wind and road noise, which is obviously less stable and is harder to adapt in real time. The high frequencies on an electric drivetrain are also more prominent but harder to decipher, and have much shorter soundwaves, meaning additional speakers will need to be positioned closer to the passenger’s ears. Without a traditional, noisy engine, you can hear noises from as low as 20-30Hz right up to the top of the hearing range. The challenge has been to cancel noises over a much wider range over the audible frequencies.
In terms of light weighting, can you tell us more about the importance of this in relation to your solution?
It’s obvious that reducing the car’s weight allows for better braking, better fuel consumption or EV range, and better performance, which already presents a benefit to manufacturers and their customers. Additionally, a lot of NVH testing is often done quite late in the production process, so any need to add additional noise insulation can result in huge additional costs, both in product and design. By using our Active Acoustics solutions, manufacturers can eliminate a significant part of the compromises caused by increased passive NVH mitigation, including the stiffening of panels and added sound deadening, even at the later stages of car development.
We are hearing a lot about the progression of autonomous vehicle technologies. How do you see your technologies playing into this movement?
In the automotive future, where autonomous vehicle tech removes certain aspects of driving, occupants will become more aware of unwanted sounds as they relax in the vehicle, such as road and wind noise. Removing this unwanted noise and creating a more pleasant acoustic environment will become a point of brand differentiation – and eventually a legislative requirement. The real benefits provided to occupants by active noise cancellation software cannot be measured in units of sound alone – the comfort or extra relief felt as a result goes beyond the quantified reduction in sound.
The last 12 months have been a pretty memorable period for everyone and for all sorts of reasons. What did you learn that you did not expect to learn?
We are lucky that Silentium already has a global team, spanning Israel, China and the UK, so we are used to the idea of working with video calls and accommodating different requirements for everyone. In addition, we have developed a range of sophisticated, PC-based software tools to help our global customers run simulation scenarios and tune our Active Acoustics solutions on their cars by themselves, with remote support from Silentium experts via web conference calls.
I’m proud of how well Silentium has adapted to the changes that have arisen because of the pandemic and I believe it has actually brought us closer together as an effective team, in both personal and working capacities.
What are the next big developments for Silentium?
Our goal is to be able to manipulate every sound in the cabin, especially speech, which is one of the hardest sounds to manage. Although not every sound can be controlled, we are actively working on creating personalised sound environments through our Quiet Bubble technology.
In the immediate term, we are focusing on refining and implementing our Active Road Noise Cancellation (ARNC) technology with a wider range of OEMs and automotive suppliers. The technology is ready, and we think all drivers deserve to enjoy the benefits that Silentium technology can offer.