SoylentNews is people
SoylentNews
Submitted via IRC for SoyCow1984
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.
"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."
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.
Source: Method to cancel noise without ear-blocking headphones
(Score: 4, Touché) by janrinok on Sunday August 26 2018, @07:04AM (8 children)
If the microphone collecting the sound is not very close to you, then the sound it will be cancelling will not be the sound that is affecting you most. For example, if the microphone is placed near wings/engines in an aircraft, but you are sat at the back or the front near another loud noise source, the sound of the engines will be reduced sure, but won't that make the local noise source easier to hear?
Multiple microphones will collect more ambient noise but it will be providing the 'cancellation' anti-phase sound to the everybody, that is not helping much either. And if you each have your own microphone - well that is what we have today with the headsets. All that has been achieved is a smaller earpiece. And if the smaller earpiece works just as well as the larger headphones, then that is what you should be marketing, not a normal wifi system dressed as IoT technology.
Perhaps I am missing something...
(Score: 0) by Anonymous Coward on Sunday August 26 2018, @08:13AM (5 children)
TFA mentions using multiple microphones if necessary. BTW, the example used in TFA is blocking out the voices of coworkers.
(Score: 0) by Anonymous Coward on Sunday August 26 2018, @08:22AM
Anyone who's ever worn noise-cancelling headphones knows that's not how it works. Ongoing, droning things, yes, e.g. lawn mowers, airplane engines, fans. Non-consistent sounds like shouting kids and chatty co-workers, not at all.
(Score: 2) by janrinok on Sunday August 26 2018, @08:44AM (3 children)
But adding the anti-phase signal to a sound that isn't bothering me from a microphone that is outside my office generates a sound that does bother me. Or is this using something else to counter noise?
(Score: 2) by janrinok on Sunday August 26 2018, @08:55AM (2 children)
Nope, same technology. And TFA explains that the microphone must be between the noise source and the user, and that a ring of microphones will be needed to provide all-round cancelling. Excuse me, the the current headsets work wherever you are, to the degree that any of this technology 'works' completely.
So each user will require a ring of IoT devices to follow each of them around for this to work? Or perhaps by providing a mesh of devices they hope to be able to direct the appropriate signal levels to all the users within the coverage of that mesh. How will they do that without knowing where you are? Oh, I know - we will track all the ear devices so we have the necessary data to process the signals in real-time (in IoT devices? Yeah, sure). People will be happy to be tracked, won't they?
It is a solution to a corner case that hasn't been thought through yet. Maybe one day it will, but not yet.
(Score: 3, Insightful) by qzm on Sunday August 26 2018, @10:17AM (1 child)
The article is also full of pipe dreams.
Why? Sound interacts, sound reflects, sound is rather nonlinear and complex in how it does these things.
You would think they would know this, however I suspect they are electronics majors looking for IoT funding, rather than people with ANY experience in acoustics.
(Score: 2) by fyngyrz on Sunday August 26 2018, @01:54PM
There's another issue. The sound that reaches your inner ear - which is where we actually hear, is shaped by our external ear. A microphone behind the ear will not hear what you hear, and so its ability to cancel is inherently crippled - its version of out-of-phase will not match your ear's version of in-phase, and so the cancellation will be wrong to some degree, moreso than if it is done in the direct sound path.
Noise cancelling headphones block a lot of what would have reached your ear, and work inside the same space as your external ear, so they can be reasonably effective.
Noise-cancelling earbuds can do the same, because they catch what is coming in and so can cancel it, and they also block the path to your ear.
How well this all works depends on several factors:
It's not at all a given that the approach outlined in TFS is even remotely (hah) practical.
(Score: 3, Informative) by qzm on Sunday August 26 2018, @10:15AM (1 child)
Its much MUCH worse than that - to the point I have to wonder if they actually understand their claimed area.
Sound is changed hugely by the environment it is in, and passes through. It reflects, it cross-interacts due to the non-linearity of air, it refracts through grating effects, and what you finally hear is dependent on the direction it arrives at your ear..
How on earth do they hope to allow for ANY of this in such a system?
Even the basics, like knowing dir direction of the source and therefore when it will arrive at the target seems.. improbably?
Of course it can be made to work with a HUGELY simplified system - noise only coming from one specific direction, and in an acoustically dead environment - due any real use? not a damn chance.
Perhaps with sozens of microphones and GFlops of realtime analysis to work out the interactions they could make some progress, but why?
They would be much better having a microphone or two outside but close to the ear and doing much easier corrections for its relative location - and even that would not be easy.
This is just poorly thought out pie in the sky stuff - no double looking for grant money rather than any real commercial practicality.
Acoustics just dont work like this.
(Score: 0) by Anonymous Coward on Sunday August 26 2018, @01:23PM
air is nonlinear for sound? I thought that happens at frequencies we can't hear anyway (or for shock waves, which i doubt we can cancel anyway).