Virtual reality has made the idea of immersively placing us into strange new landscapes — whether real or imagined — not only plausible, but commonplace. But what about sound?
Up until now, there’s been no convincing way of truly replicating the sound environment of different locations from the comfort of one room. That’s now changed thanks to groundbreaking work from researchers at Denmark’s Aalborg University, Finland’s Aalto University, and sound pioneers Bang & Olufsen.
What they’ve created is a basement sound laboratory able to accurately reproduce the acoustics of any environment ranging from a car to a concert hall.
The project, Aalborg researchers told Digital Trends, started with the question of how to test sound systems in multiple locations. One answer would be to physically move a speaker from room to room: something which is both inefficient and impractical, given that our memories for how sounds, err, sound tend to be extremely sketchy.
Several year ago, Aalborg University researchers developed a method for cleverly recording sound in different locations — complete with environment factors — and then playing it back via headphones.
“There are so many possible applications for this technology that it’s like asking what it’s possible to record with a microphone.”
As answers go, it wasn’t bad — and in many cases works just fine. But it’s not perfect.
“The problem is that headphones don’t give a user the full effect of hearing sound in a room.” Søren Bech, a professor in Aalborg’s Department of Electronic Systems, told Digital Trends. “For example, if there’s a heavy bass you won’t feel that low frequency impact in your chest. You don’t get all the reverberations you get if you walk into a room.”
Thankfully, a brilliant Ph.D. student named Neofytos Kaplanis (“Neo” for short) came up with an answer.
“What we can now do with this technology is to go to a room and take many measurements with a special microphone,” Kaplanis told Digital Trends. “You then save that information on your hard drive, and use software to work out how the sound is distributed in a room. That’s important because when you’re listening to a sound system, you’ll hear the sound directly from the speaker, but you’ll also get reflections from the floor, the walls, and other details about the room you’re in. Our system can tell you where every one of these reflections comes from. When you then listen back to it in our sound lab, you get the entire experience as if you were there — and you don’t have to listen to headphones to get it.”
The sound lab at Aalborg University is comprised of 40 small speakers and three subwoofers positioned around a narrow walkway. In the room there is barely enough space for a chair, particularly when the walls are covered in thick, pointed foam padding for absorbing sound that hits it. However, the effect is so uncannily realistic that Kaplanis said that — when test subjects enter the darkened room — they firmly believe they’re hearing sounds from a couple of hundred feet away, depending on the simulation being run.
Søren Bech described the sound models the researchers create as the “fingerprint of a room in three dimensions.” As more and more sound files are recorded in this way, it will result in a audio library that can quickly test out new speakers in any setting.
Even more impressively, it’s so accurate that it doesn’t just model the room, but also allows the researchers to simulate the change of positioning of a single speaker within said room.
So what’s this amazing research going to be used for? At present, Bech and Kaplanis said that a major application is for testing speaker systems for new cars. Particularly in high-end luxury vehicles, sound systems are an important selling point. In partnership with Bang & Olufsen, automotive manufacturer Audi has already mapped out the acoustic conditions of many of its vehicles. Would-be buyers can try on a pair of headphones and VR goggles and then test out different interiors and sound systems in their possible future car.
Technology like the newly-developed headphone-free sound experience will make this even more compelling, and can help car designers as well as customers.
“Basically, whatever you can simulate, you can recreate in the room,” Kaplanis said. “Even if a location doesn’t physically exist, as would be the case if an architect is designing a concert hall, you can find out how it will sound when it is built. There are so many possible applications for this technology that it’s like asking what it’s possible to record with a microphone. You can do virtually anything you can think of, right?”
