We talk a lot about road, tyre and engine noise when reviewing cars, applauding the quieter vehicles for their clever sound-deadening measures.
But these days, it's not enough just to minimise noise in a car – you have to eliminate it entirely.
Enter the era of noise cancellation in cars – the same concept utilised in those fancy headphones everyone uses on planes, but extended to an entire car.
Only a small handful of Australian vehicles currently offer noise cancellation, but the technology is constantly developing and expanding, so expect to see it on more vehicles very soon.
If you’re not well-versed in the intricacies of removing noise from a big, hulking hunk of moving metal – allow the experts to explain.
How does noise cancellation in cars work, in layman's terms?
To understand the intricacies of noise cancellation in cars, we went straight to the experts at Bose, makers of the aforementioned fancy headphones and pioneers of noise cancellation technology.
Bose has been developing its in-car technology – known as Engine Harmonic Cancellation or EHC – for over a decade and it first appeared in the 2011 Cadillac Escalade and Infiniti M sedan in the United States.
To minimise undesirable engine and powertrain noise, “EHC gathers data input from the engine and from strategically placed microphones inside the vehicle cabin to calculate the appropriate noise cancelling signal, which is delivered through the audio system’s speakers," a Bose spokesperson told CarAdvice.
“The technology is highly targeted and precise, aimed mostly at lower frequencies produced by the engine – typically deeper booming or groaning sounds.”
Of course, how the technology is enacted varies from manufacturer to manufacturer, but the basic principles are the same.
Jaguar Land Rover, for example, calls its system ‘Active Road Noise Cancellation’ and uses sensors on each wheel of the vehicle to monitor road surface vibrations so the appropriate level of cancellation can be played through the car’s sound system.
Hyundai recently announced its own new-and-improved sound elimination technology, called "Road-Noise Active Noise Control" (RANC), which promises a "nearly silent" cabin by using acceleration sensors to monitor vibration and emitting inverted soundwaves to counteract the incoming noise.
Is it like noise cancelling headphones?
While they both use similar physics, Bose’s noise cancellation for cars differs from its system for headphones and smaller appliances.
“Bose noise-cancelling headphones cancel a wide band of sound frequencies in the small, controlled environment inside each ear cup [whereas] Bose EHC targets a narrow band of low-frequency engine noise throughout the much larger space of a vehicle cabin,” the Bose spokesperson explained.
“The specific targeted frequencies are identified by car makers to achieve their desired sound characteristics. Bose engineers then customise the solution for the unique acoustics of each vehicle.”
What kinds of noise can be removed? What can’t?
For the most part, noise cancellation on cars removes road noise, exhaust sounds and tyre noise – anything that can generate some vibrations.
In Jaguar Land Rover cars, the Active Road Noise Cancellation system (ARNC) is capable of lowering outside noise in the cabin by the equivalent of turning down the in-car sound system by four ‘steps’.
Otherwise, don’t expect it to be completely silent, with car horns, other traffic noises, ambient sounds of the outside world and music still able to penetrate the cabin.
Above: the 2021 Jaguar XF, which features noise cancelling technology.
What are the benefits of noise cancellation in cars?
The main benefit of noise cancellation is that it reduces driver distraction and can help prevent driver fatigue.
“This technology will enable a significant reduction in exposure to low-frequency noises up to 300Hz which can help prevent driver fatigue on longer journeys,” a Jaguar Land Rover spokesperson told CarAdvice.
“Fatigue affects the ability of a driver to deal with hazards or unexpected events, with tired motorists recording an average reaction time increase of 16.72 per cent compared to those fully alert.”
Additionally, most manufacturers use technology that is lightweight to ensure a car’s handling characteristics are unaffected.
The cars in Australia with noise cancellation capabilities
While noise cancellation isn’t a new technology, its roll-out across the automotive industry has been a little slower – but several new cars will feature the capability locally.
Bose says Australian buyers will first spot its noise cancelling system of the incoming C8 Chevrolet Corvette Stingray, which is expected in 2021.
Honda has also been using the technology in some capacity since the early 2000s – calling its version ‘Active Noise Control’.
Buyers can currently find it on Accord and CR-V (all grades exception Vi) models, as well as on the recently released mid-life update of the Civic Type R, where this system is called Active Sound Control and is actually designed to enhance engine noise in certain drive modes and refine it in others.
“Based on the science of digital signal processing, RANC overcomes the limitations of existing noise control technologies that rely on physical technology, such as materials and body structures, to quiet the cabin,” Hyundai said in a statement.
“RANC generates sound waves of opposite phases in 0.002 second by analysing road noise in real time, dramatically reducing irregular, simultaneous road noise.”
Other brands and models also feature similar noise-cancelling systems, though for now the technology is usually found in more expensive models or on flagship variants. As with most technologies, it is expected to trickle down to more affordable models quickly.
Get ready for a very quiet future.
Above: The 2021 Genesis GV80.
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