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MyNoise – Background Noise Generators

mynoise.net

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Re: MyNoise – Background Noise Generators

#21

Post by mrtksn »

ssl232 wrote: post #7

I expected a website offering to use your microphone to record, invert and cancel background noise via the speakers. Turns out the website is offering prerecorded sounds instead, not really cancelling anything. Still though, surely someone has tried my idea? It would likely need some adjustability to match the phase delay between microphone and ears-via-speakers but I guess it could work.

> Still though, surely someone has tried my idea

Well, AFAIK some cars have active noise cancelation. I wonder why we don't have it at homes, after all they are both confined spaces. If general purpose computation and software wouldn't cut it, why we don't have whatever they have in those cars? A lot of money is spent on noise insulation on buildings, so the demand and the money must be there.

Re: MyNoise – Background Noise Generators

#22

Post by alexdbird »

mysterydip wrote: post #16
ssl232 wrote: post #7

I expected a website offering to use your microphone to record, invert and cancel background noise via the speakers. Turns out the website is offering prerecorded sounds instead, not really cancelling anything. Still though, surely someone has tried my idea? It would likely need some adjustability to match the phase delay between microphone and ears-via-speakers but I guess it could work.

Could it work for cancelling tinnitus? Just have an inverse of that sound playing, with some controls for frequency adjustment for individuals.

I don’t think so. Most tinnitus isn’t an actual sound wave. It’s coming from a glitch in the auditory system. Even if your input was mixing and could theoretically cancel it out, it would be impossible to lock the phase (without some feedback from deep inside your head!)

Re: MyNoise – Background Noise Generators

#24

Post by wowokay »

shreyshnaccount wrote: post #8
ssl232 wrote: post #7

I expected a website offering to use your microphone to record, invert and cancel background noise via the speakers. Turns out the website is offering prerecorded sounds instead, not really cancelling anything. Still though, surely someone has tried my idea? It would likely need some adjustability to match the phase delay between microphone and ears-via-speakers but I guess it could work.

I don't think it can be done.. active noise cancellation needs to be really really fast and is done using dedicated hardware afaik.

And for some reason I thought it required triangulation, in that noise cancelation can't be done with sound in a space because the inverse of the sound you hear is relative compared to the person a foot or two away from you.

Re: MyNoise – Background Noise Generators

#25

Post by [deleted] »

the__alchemist wrote: post #17
shreyshnaccount wrote: post #8

Earlier quoted context omitted.

I don't think it can be done.. active noise cancellation needs to be really really fast and is done using dedicated hardware afaik.

Yea. Relatively straightforward on an MCU that supports audio, and running non-OS firmware. I think anything that runs through an OS or schedule would introduce too much latency. So, it can be on a generic MCU, but not one where the algorithm is competing for CPU time with other processes.

[deleted]

Re: MyNoise – Background Noise Generators

#26

Post by srean »

Apart from speed of response that many comments mention, isn't there a more fundamental issue with active suppression using wave interference in a 3D space. There will be places where the superposition of the amplitudes of the original wave and the active/added wave will cancel each other out but there will be places where they will superpose additively. Hypothetically one could position the source of the active suppressing waveform where the suppression target originates, but that would not be practical. Of course, with smart and speedy enough tech one could arrange the waves to cancel at a specific point.

Re: MyNoise – Background Noise Generators

#27

Post by hackerlight »

wowokay wrote: post #24
shreyshnaccount wrote: post #8

Earlier quoted context omitted.

I don't think it can be done.. active noise cancellation needs to be really really fast and is done using dedicated hardware afaik.

And for some reason I thought it required triangulation, in that noise cancelation can't be done with sound in a space because the inverse of the sound you hear is relative compared to the person a foot or two away from you.

It does only if the microphone is far away from the ear canal.

If it's close to the ear canal, all you need is low latency hardware (or hardware+software), responding in a few milliseconds thereabouts.

Re: MyNoise – Background Noise Generators

#28

Post by shreyshnaccount »

the__alchemist wrote: post #17
shreyshnaccount wrote: post #8

Earlier quoted context omitted.

I don't think it can be done.. active noise cancellation needs to be really really fast and is done using dedicated hardware afaik.

Yea. Relatively straightforward on an MCU that supports audio, and running non-OS firmware. I think anything that runs through an OS or schedule would introduce too much latency. So, it can be on a generic MCU, but not one where the algorithm is competing for CPU time with other processes.

you prolly need a dac or smth, because embedded devices usually don't have the compute needed for real time noise cancellation

Re: MyNoise – Background Noise Generators

#29

Post by mihaaly »

ssl232 wrote: post #7

I expected a website offering to use your microphone to record, invert and cancel background noise via the speakers. Turns out the website is offering prerecorded sounds instead, not really cancelling anything. Still though, surely someone has tried my idea? It would likely need some adjustability to match the phase delay between microphone and ears-via-speakers but I guess it could work.

Try the app.

That is generating neverending background noises in a certain selected theme (forest, rain, ocean, zen garden, white noise, ...) and the components can be tuned to our liking (i.e forest, with the amount of wind and bird and other effects one likes).

Quite good! I use that.

(noise cancelling term is misleading btw. More like covering noise with another noise. : ) )

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