Illinois researchers develop
method to cancel noise without ear-blocking headphones
August 27, 2018
noise is almost everywhere, from people talking in the office corridor
to road construction down the street to the neighbor's lawn mower.
Research being conducted at the University of Illinois' Coordinated
Science Laboratory is looking to improve this noisy frustration.
Current noise cancelling technology comes in the form of headphones and
earbuds. To cancel noise, these headphones emit an anti-noise signal to
contrast the external sounds. The time available for the headphones to
produce this anti-noise signal is extremely short. This results in some
noise getting through, which is why all these devices must cover the
entire ear with noise-canceling material. However, wearing such
ear-blocking devices for long periods of time is not comfortable, and
can even be harmful.
shows how the new noise cancellation system would work. Transmitting
sound via a wireless network more quickly than sound travels alone.
"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
The main idea behind this research involves combining wireless IoT
networks with noise cancellation. A microphone is placed in the
environment that senses sounds and sends them over wireless signals to
an earpiece. Since wireless signals travel a million times faster than
sound, the earphone can receive the sound information much faster than
the actual sound itself.
"This is similar to lightning and thunder -- the lightning arrives much
before the thunder, allowing people to prepare for the loud rumble,"
said Shen's advisor, 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."
The figure below (and the attached video) shows an example of how this
technology would work. The person who wants to cancel noise (Alice)
would place the IoT microphone away from her, say on her office door.
The noise from her coworkers' conversation in the hallway is picked up
by this IoT device and transmitted to Alice's earpiece over a wireless
connection. The actual sound arrives at the earpiece later, and because
of this lead time, the noise can be fully canceled. As a result, it is
no longer necessary to block the ear canal.
There are however, a few limitations. The IoT microphone needs to be
between the noise source and Alice. If noise is coming at her from all
directions, a couple more IoT devices would need to be placed around
her. In tests conducted during the research, the device designed by Shen
and Choudhury's group outperformed a leading headphone in overall noise
cancellation and was rated better by the human participants.
When asked about the potential privacy concerns involved with the
device, Shen nullified some of the most common fears.
"The most common privacy concern is that the device will secretly record
someone's voice," Shen said. "This device is analog, so it has no
capacity to record the sound. The moment the device hears the sound it
is sent out wirelessly."
This differentiation is what separates Shen's device from many IoT
devices commonly used today, such as Amazon Echo and Google Home, which
must record voice samples in order to operate.
and his colleagues are already receiving attention for their work. The
research paper about the project was recently selected for presentation
at the upcoming Association for Computing Machinery Special Interest
Group on Data Communication (ACM SIGCOMM) Conference which takes place
in Budapest, Hungary, in late August. The conference brings together
global researchers across the field of computer networking and
"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," said ECE Assistant Professor Haitham
Hassanieh, who is a co-author on this paper. Other co-authors include
Nirupam Roy and Junfeng Guan, both ECE Ph.D. students at the University
of Illinois Urbana-Champaign.
Looking forward, the team would like to expand the use of their device
to provide noise cancellation for more than one individual at a time and
make the wearable device even lighter for continuous use.