28.08.18

Wireless signals could block unwanted noise

Wireless IoT networks could hold the key to superior noise cancelling systems.

In a bid to reduce disruptive noise, scientists at the University of Illinois have developed a system that uses wireless signals to quickly detect noise interference before the sound waves reach a person’s ear. The research, conducted by the university’s Coordinated Science Laboratory, outlines a system that removes the need for ear-blocking headphones. 

The researchers outline that current noise cancelling technology in the form of headphones and earbuds emits anti-noise signal to cancel out external sound. Because the sensor is located within the headphones, the time to produce the anti-noise signal is short and allows some noise to get through. In a bid to combat this manufacturers have produced products that cover the wearer’s entire ear with noise-cancelling material. 

The new solution places a microphone in the environment as opposed to the wearer’s headphone. This can sense sound and send signals to an earpiece via wireless signals. Those signals will travel a million times faster than sound and will alert the earpiece as to which sounds need to be cancelled before they even arrive. 

“This is similar to lightning and thunder -- the lightning arrives much before the thunder, allowing people to prepare for the loud rumble,” said Romit Roy Choudhury, an ECE Professor. “Similarly, our ear device gets the sound information in advance, and has much more time to produce a better anti-noise signal.”

So the solution removes the need for ear blacking devices, which can be bulky, uncomfortable and even harmful for long term use. It also promises to change the way noise cancellation in certain environments is approached in the future. 

“Our goal is to not block the ear canal,” said Sheng Shen, lead author and a Ph.D. candidate in the Coordinated Science Laboratory and Dept. of Electrical and Computer Engineering (ECE). “We envision a behind-the-ear device that still achieves noise cancellation as good as the best headphones or earbuds available today.”

But there are some limitations. Without a number of microphones, noise would only be able to be blocked from one direction.

But in response to privacy concerns, researchers reassured that the microphones were incapable of recording sound. 
“The most common privacy concern is that the device will secretly record someone’s voice,” Shen said. “This device is analogue, so it has no capacity to record the sound. The moment the device hears the sound it is sent out wirelessly.”

Future plans include expanding the system to provide noise cancelation for multiple people and making the wearable device even lighter. 

“This is bound to change the way we think of noise cancellation, where networks of IoT sensors coordinate to enable quieter and more comfortable environments,” confirmed ECE Assistant Professor Haitham Hassanieh, who is a co-author on the research paper.

Other co-authors include Nirupam Roy and Junfeng Guan, both ECE Ph.D. students at the University of Illinois Urbana-Champaign.