The technology behind noise-canceling headphones has been around since the 1970s, but in recent years, the technology has been brought to broader applications.

Noise-canceling headphones are arguably one of the most popular consumer devices on the market. Designing the next, best noise-canceling device is a challenge that engineers around the world are tackling. Finding the next form factor beyond headphones, however, is a difficult prospect. Here are some such ventures that may become or at least inspire the next noise-cancellation device. 


How Do Noise-Canceling Devices Work?

Before we take a look at some designs for noise cancellation, we should brush up on the basics concepts behind noise-canceling devices (not to be confused with noise in circuitry). The concept is actually quite simple.

A noise-canceling device records surrounding noises through a microphone and plays "complimentary soundwaves" that cancel the noise coming into the device through its speakers. There is a slight delay between the sound waves being picked up by the microphone and the speaker playing complementary soundwaves to cancel out the noise that the microphone picks up. At this point, the circuitry in the headphones runs an algorithm (somewhat similar to adaptive echo cancellation) to produce the complementary sound waves. Because of this delay, noise-canceling headphones and other devices are very good at canceling steady noises like loud engines but aren't very effective at canceling noises.

Insulating large areas with noise-canceling technology is incredibly expensive so, for the most part, that is only done in the cockpits of airplanes. The cost of making larger noise-canceling areas has had the technology at something of a stalemate for consumer devices, but a few startups are trying to change this.


Recalm: AI in Noise-Canceling Tech

Recalm is a German startup located in Hamburg that recently acquired an EXIST grant in order to research and develop prototypes for noise-canceling devices that aren't bound to headphones. The applications the team is trying to tackle are noise canceling attachments for various machines and engines that produce a lot of noise. The team says that they've developed a smart algorithm that uses artificial intelligence to cancel noise actively. In theory, this should make the process of recording incoming sound and producing complementary sounds much faster. 


Two of Recalm's founders: Marc von Elling, Martin Günther, and Lukas Henkel. Image courtesy of Recalm.


There is next to no documentation available on how their device works. When asked about how their technology works in an interview with Hamburg News, Lukas Henkel, one of the cofounders only said "The microphone absorbs the noise and sends an electric signal to the microprocessor. An algorithm generates an anti-noise signal of opposite polarity via the loudspeaker and sends it to the noise source. The noise is eliminated by destructive interference."

So, basically, he described noise canceling headphones with no detail whatsoever about how they would make the noise cancellation scale to a larger area. In all fairness, Recalm went about acquiring funding in an ethical way. The team has made no guarantees that their prototype will work—instead, they're focused on researching the technology because they think it will be a victory for public health if they can pull it off. If they make working prototypes that aren't incredibly expensive, there will certainly be a market for it.


The Helmfon: From Headphones to Helmets

The Helmfon is a noise-canceling helmet designed by a Ukranian design firm called Hochu Rayu. The Helmfon is made from specialized materials that reflect outside noise and has circuitry inside for noise cancellation and a dock for your smartphone. Unlike Recalm, the Helmfon utilizes proven technology but doesn't quite as ambitiously tackle the concept of a noise-cancellation space. Like Recalm, however, the Helfon is still a prototype.


Just another day at the office... Image courtesy of Hachu Rayu


The main innovation that Helmfon offers is that it places noise-canceling headphone technology around the head instead of in the ear. I've never worked in an open office in Eastern Europe, so I can't speak for consumers worldwide, but I don't know anybody who wants to carry their cubicle on their head like some kind of hermit crab.


Sono and Muzo: Wall-Mounted Noise-Cancellation

Here's a case of two devices that were developed independently but are essentially the same thing. Sono generated a lot of buzz in 2013, then fell off the face of the earth when they couldn't produce a working prototype. Sono required a window as a barrier instead of trying to create a "noise-canceling bubble." 


Sono was supposed to cancel noise using a window as a barrier.


Fast forward to 2016 when a company called Celestial Tribe raised over $2 million with crowdfunding campaigns on Kickstarter and Indiegogo. The amount of funding generated for Muzo was incredible, which demonstrated that there was a market for the device. Over a year after Muzo's estimated delivery date, however, only a few people have actually received theirs.

The few people who have received them have been testing their models. The current verdict? It kind of works, but is more of a white noise generator. The backers are surprisingly patient in the Kickstarter comments, but some have their torches and pitchforks at the ready. Some people feel that this is just part of the crowdfunding process while others feel like they were scammed, but such are the harsh realities of crowdsourced device design.


Different Form Factors, Same Goal

Obviously, at this point, headphones are the most popular form of noise cancellation because they work, but what do you think will be the first successful form factor to go beyond that? I'm leaning toward the window sticker because it filters noise through a barrier.