As far as highways go, this one in South Korea is relatively smooth. No serious potholes or pavement cracks, but plenty of little bumps and divots. The newly unveiled Genesis GV80 SUV easily absorbs these imperfections, and so the only disruption inside the minimalist, seven-seat cabin is a whisper of wind noise. Notably missing from the acoustic picture is rushing air’s stalwart companion, roaring tires.
Usually, if you can’t hear the rolling rubber, it’s because your automaker made all sorts of microscopic suspension and sound-deadening adjustments, and worked with the tire manufacturer to tweak everything from the tire’s compound to its tread design. These standard approaches have their limits. No amount of tuning can account for every type of surface a car can encounter, and replacement tires rarely match the original rubber. Moreover, traditional sound-deadening moves are often nixed in the name of weight reduction to aid fuel economy or battery range.
The GV80 is silent, though, thanks to a flexible, digital solution that Genesis, Hyundai’s luxury arm, decided to call Road Noise Active Noise Control. Noise-canceling systems are already fair common in luxury cars (as well as in headphones). Typically, they use microphones in the cabin to capture ambient noise, which a processor then uses to generate a constant “opposite” sound wave that is pumped through the car’s stereo speakers.
But, according to Hyundai, these are mostly good for muting steadily running engines. Tire noise varies more from mile to mile and at different speeds. It demands a smarter system.
“We have multiple microphones in each of the wheel wells,” says Albert Biermann, who leads R&D at Hyundai. His team also deployed vibration-calculated accelerometers, amplifiers, and a digital signal processor to analyze the complete signals. The system distributes the cancelation sound through the car’s speakers. Each seat receives a dedicated signal tailored to what the car’s interior mics detect at each position. “You need a lot of calculating power to reduce the noise, since the system responds to the unique acoustic signature of each tire, even as that signature changes over the tire’s life,” Biermann says.
Hyundai says the system cuts in-cabin noise in half, by 3 decibels. I wasn’t able to try it with the system deactivated, but those estimates seemed accurate in the hour on the highway I spent in the GV80, at different speeds and in different seats.
Controlling noise will only become more important as Genesis moves to launch its first electric car, a battery-powered sedan. Without the rumbling of an engine, people in EVs can detect road and wind noise at 40 mph, compared with 60 mph in conventional cars, according to Hyundai. Expect to see the new car on dealer lots in 2021—but don’t expect to hear it.