A new research is being conducted by the University of Illinois’ Coordinated Science Laboratory to solve the problem of noise cancellation. The current noise cancelling technology exists in the form of headphones and earbuds. These headphones emit an anti-noise signal to contrast to the external sounds to cancel noise.
The time that is available for the headphones to produce this anti-noise signal is really short. This leads to some of the noise getting through, which is why these devices must be equipped with noise-canceling material. The entire ear must also be covered by this material, but wearing such ear-blocking devices for a long time is not comfortable, and can also be harmful.
“Our goal is to not block the ear canal,” said Sheng Shen, the lead author of the study 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.”
The idea behind this study involves combining the wireless IoT networks with noise cancellation. A microphone is fixed inside that can sense sounds and sends them over wireless signals to an earpiece. Because wireless signals are 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 Romit Roy Choudhury, Shen’s advisor and also an ECE Professor at the University of Illinois. “Similarly, our ear device gets the sound information in advance, and has much more time to produce a better anti-noise signal.”
The figure above shows an example of how this technology would function. The person who wants to cancel the noise would place the IoT microphone away from herself (Alice), let’s say on her office door. The noise from her coworkers’ conversation is picked up by the IoT device and then transmitted to the person, but the actual sound reaches the earpiece later, because of this time difference, the noise can be fully canceled. So it no longer a requirement to block the ear canal.
But there does exist a few limitations. The IoT microphone should be between the noise source and the person who wants to block the noise. If the noise is coming from all the directions, some more IoT devices would need to be placed around the person.
When the research team was asked about the potential privacy concerns that the device brings with itself, Shen nullified some of the most common fears. “The most common privacy concern is that the device will secretly record someone’s voice,” said Shen. “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.”