Hi peeps,
I had an idea on the airplane today. I am sitting there wishing my headset would cancel the noise instead of deaden the noise. When I realized that my Android's microphone could listen to the noise and send negative sound waves to the earphones resulting in noise cancellation. Can someone build this application?
There should be a range control to control what type of noise i canceled and a control that would allow more or less cancellation. And of course the volume to the headset should still work. Would be nice if movies and audio files could also be played.
Also, don't attempt to make money on this idea because I am claiming this idea for the open source community.
I was actually thinking about this the other day. I cant really see much of a reason the normal mic couldnt be used to cancel ambient noise
Great idea, can't imagine the mic being high enough quality for this to be effective.
I think using the handsfree mic would be a better option as the phone spends most of its time in your pocket.
mercianary said:
Great idea, can't imagine the mic being high enough quality for this to be effective.
I think using the handsfree mic would be a better option as the phone spends most of its time in your pocket.
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Im not sure about others but my phone is basically always in my hand. I text like crazy and rarely have time to put it away
mercianary said:
Great idea, can't imagine the mic being high enough quality for this to be effective.
I think using the handsfree mic would be a better option as the phone spends most of its time in your pocket.
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Not sure about the mic quality until someone tries.
My earphones don't have a mic and it wouldn't be to much trouble to leave it out of the pocket when using the noise canceling feature. Could also be done so the phone mic only cancels the noise it hears to and the boom mic would still work normally. So the person on the other end would hear less noise.
I need someone to write the program?
No developers wanna try? I'll be a tester.
Noise cancelling wouldn't be that easy, the delay of capturing, processing and creating the cancellation sound stream would make the sound cancelling ineffective. Have a look on wikipedia for "Active Noise Control".
Such a feature would be damn amazing though. I hope someone might be able to prove me wrong.
NeoAcheron said:
Noise cancelling wouldn't be that easy, the delay of capturing, processing and creating the cancellation sound stream would make the sound cancelling ineffective. Have a look on wikipedia for "Active Noise Control".
Such a feature would be damn amazing though. I hope someone might be able to prove me wrong.
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I would think the delay would be very small and not noticeable, but maybe I am wrong?
Instead of active noise cancelling for all sounds, some sounds are predictable once sampled. The hum of an airplane for example doesn't really change that much. Woulnt someone be able to sample a ~5 second clip and then process that, and repeat it?
Sent from a touch tone tele-phone.
bivio said:
Instead of active noise cancelling for all sounds, some sounds are predictable once sampled. The hum of an airplane for example doesn't really change that much. Woulnt someone be able to sample a ~5 second clip and then process that, and repeat it?
Sent from a touch tone tele-phone.
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Yeah maybe you could have a noise canceling app or something that you run and it listens with the mic and makes a sample to use while you play your music or whatever, then just listens for changes, loud noises, etc to actively cancel rather than constantly listening and using everything.
Sent from my SCH-I500 using Tapatalk
Maybe that could be the difference between a paid and free app.
Free = just cancels out bacground noise
Paid = cancels out background noise and "impact sounds"
Sent from a touch tone tele-phone.
As previously stated, i doubt active noise cancelling would really be that effective due to many reasons, mic quality, latency issues, etc.
As for pre-recorded noise cancelling, there's probably a reason it hasn't been done yet. It's probably either incredibly hard to do, or incredibly ineffective.
...although, i'd love to be proven wrong
Yeah, this is just too precise a task to do with anything but real-time electronics. A typical noise cancelling setup uses an inverting op-amp that sends an inverted signal at the exact time that it is generated. Any latency at all (anything above a few nanoseconds) would cause an echo effect that would be worse than the noise. There's just no way a microprocessor could sample the sound, analyse it, and generate an inverted signal in software that would be anywhere near fast enough.
As for eliminating random noise based on some pre-sampled or randomly generated noise (white, pink, etc.), we have that already. It's called treble.
Gene Poole said:
There's just no way a microprocessor could sample the sound, analyse it, and generate an inverted signal in software that would be anywhere near fast enough.
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I don't think you need to analyse anything just invert the signal and feed back out. But I do understand your point. These processors are doing millions of operations a second so I would hope just maybe it is possible? Maybe the sound processing chip has a built-in invert function? This is just my humble opinion and if you are in fact a person that does this for a living I submit to your wisdom.
there is an app called sound canceller that does this.
however, it seems not to work very well supposedly because of the API having a delay to playback
There seem to be some serious misconception about Noise Cancelling here. So listen to Gene Pool, he knows what he's talking about. Please read up on your wave physics and NC details:
http://en.wikipedia.org/wiki/Noise_cancelling
http://en.wikipedia.org/wiki/Noise-cancelling_headphones
Gene Poole said:
... A typical noise cancelling setup uses an inverting op-amp that sends an inverted signal at the exact time that it is generated. Any latency at all (anything above a few nanoseconds) would cause an echo effect that would be worse than the noise.
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I almost agree, apart from that your measure is about 6 orders of magnitude (10^6) off! At 1000 Hz, it should be enough with a delay that is slightly less than double that frequency for a 180 degree phase shift. I.e. ~1 ms (millisecond).
sonwon said:
I don't think you need to analyze anything just invert the signal and feed back out.
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That's right, and this make the electronics very simple, so yeah, it's probably easier to just buy yourself a pair of noise cancelling head/ear phones. (Why not ALL head/ear-phones doesn't already have built in NC, is beyond me. But I guess its a big difference between "descent" and "good" NC...)
xd4d3v said:
there is an app called sound canceller that does this. however, it seems not to work very well supposedly because of the API having a delay to playback
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Like I said above, you just need to make sure your App is running with higher priority than everything else, to minimize the latency. I suppose putting the phone in "Airplane Mode" would help... But ANYTHING running on your phone would create latency, as anyone running MIDI keyboard software on a PC know all about, where a latency of 40 ms is already annoying and very noticeable. While it is nearly impossible to obtain latencies less than 10 ms on a normal operational PC without special low latency HW.
Here are some interesting sound apps:
https://market.android.com/details?id=org.liberty.android.noisecanceller
https://market.android.com/details?id=com.idroidbot.acousticsfilter
https://market.android.com/details?id=com.idroidbot.ispectral
(I have not tried any of these, so I can't really recommend them.)
On the last note. Most phones already have built in NC HW, so if you can figure out how to use that, you would probably have something very interesting going. For example see my post on the noise-cancellation problem on the Samsung Galaxy S2.
http://forum.xda-developers.com/showthread.php?t=1384756
E:V:A said:
That's right, and this make the electronics very simple, so yeah, it's probably easier to just buy yourself a pair of noise cancelling head/ear phones. (Why not ALL head/ear-phones doesn't already have built in NC, is beyond me. But I guess its a big difference between "descent" and "good" NC...)
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That, and NC is only "decent" at most anyway. It's good to listen to music and such in public transports but absolute crap to use when you're in a quiet room at home. I wouldn't want NC technology to be implemented on "audiophile grade" headphones (audiophile jokes apart).
Has anyone tried any of the apps that E:V:A listed? If so, how did they work?
If this helps, my Galaxy Note cancels noise during calls, and it is done with the onboard mic itself obviously.
Regarding how good is it: I was on a railway station with trains arriving and departing, passengers moving around with trolleys and public announcements in loud volume when my friend called and he thought I'm in my apartment. I made him listen to the noise but he could hear nothing.
This happens all the time!
(also, the friend v.akhilverma here, purchased note himself)
Noise cancellation is far more complicated than just inverting an input and summing it with the output. If it were that simple then there would have been low cost noise cancellation headphones a very long time ago.
That being said, we live in an era of mega-powerful DSPs everywhere. Your phone's ARM processor is even powerful enough to do the DSP necessary for simplistic noise cancellation. I am writing a noise cancellation app right now and should be done with it in a few weeks. I will post a link here when done.
By some rough initial performance metrics it should be completely feasible to run a software noise cancellation algorithm with a 12 tap IIR filter and a minimal RLS equalizer. I've already written the C code to do the noise cancellation, and I just need to port it to NDK and find a way to have it run on the phone when audio is playing (and not when audio is not playing).
I'll post a link here when it is working.
I was wondering if anyone charges or tethers their phone by the USB port on the dock. And if u have any issues doing so. I tried and I can hear an odd whiny buzz sound from the connection. It would be nice to do as long as I am not going to fry it. So if you have been doing this without problems for awhile plz drop a line about ur experience.
I am tethering my EVO 4G to charge the battery. Haven't noticed any buzzing. Using WiFi Tether for the Internet.
Sent from my Transformer TF101 using Tapatalk
The sound is extremely quiet. I have to put my ear close to hear it clearly.
zedorda said:
The sound is extremely quiet. I have to put my ear close to hear it clearly.
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If that's the case I wouldn't worry too much. If it was loud enough to be heard from a distance, or over ambient noise then I would take a closer look at it. Electronics does make all sorts of noises (think of the old flyback transformers in televisions before they became all solid-state), especially if considerable current is going through it. Also flyback transformers are still used but on a smaller scale in switching power supplies. They generally operate in the 15-22kHz range. I bet you're a very young person since most people by time they hit their mid-20's lose the high-end of their hearing due to normal aging (faster if they listen to loud music/attend concerts like I did).
Sorry if this is in the wrong section but dont know where to post this, as my phone is as of yet not really been devloped by anyone except that it has been rooted. theres no roms for it yet.
Its an alcatel one touch 983, which is an entry level android phone but with fairly decent specs. As it has a 1ghz broadcom processor and 512mb ram.
anyway , I have a brilliant app which i have paid for called Audiotool. which is a fully featured Real Time Anyliser for audio use. all anyliser functions work as expected.
The problem happens when using the headphone jack to output to speakers. The software has a generator utility used to generate pure tones, white noise, pink noise and even has a polarity checker. Which is really handy for working with Venue sound systems.
Obviously once you plug in a headphone jack it switches to headset mode and cuts of the phone mic. Audio output is still fine and you get the full range. But when you use the program to swtich to front mic to get the mic working again, all bass is lost. Which makes some of the functionality of the app useless, like polarity checking of bass speakers or low frequencie response.
Ive already contacted the developer and he confirms that his app does not apply any filters to audio out and that sound from the app should be exactly the same between using headset mic and phone mic, so it must be the phone that is applying a roll of filter. But unfortunatly as he doesnt have my model of phone to test on cant fix.
Anyway this seems to make sense as rolling of frequencies that the phone speaker cant really produce would be there to protect it, but it shouldnt be doing that while headphones are still plugged in. The headset icon is still on even when using the phone mic but bass frequencies coming from the headphone jack on the phone are definatly being rolled of. If i go mack to main mic bass frequences return but mic doesnt work.
Im wondering if this is a bug in the OS on how it functions to switch between headset mic and phone mic or if theres some kind of solution to stop it from doing that.
Im running a stock rom 2.3 android.
Not sure if there is a free version incase anyone wants to test it on there phone.
no ideas how to stop this odd behaviour?
Hey guys, does anyone else experience some quiet continuous popping and electrical sounds coming from inside the back of the tablet? If I put my ear on the back, it pretty much sounds like continuous popping and something like a laptop HDD running.
It's not that bad but gets noticeable in a quiet room especially on tegra apps, even dabbler.
I know it has a desktop GPU chip inside and I know this is common in desktop video cards but is this normal on this tablet?
Sent from my SHIELD Tablet using XDA Free mobile app
I've got the same thing.
The tablet had fan cooling system inside I believe.
Sent from my SM-N910T using XDA Free mobile app
Hissing mechanical noise during load...
I too have noticed this on my lte unit first night use.
I might be talking about something else, although regarding the hissing noise similar to harddrive (i dont really get the popping noise, nowhere near loud PoP sounds)
I can relate this noise very similar experience ive had on my computer with low level (in anotherwords cheap) onboard sound card -chip. Board was made by intel for dell. Basically it did the very close, in moments when hdd&ram cooperated in that computer under high cpu load, this sound came from the computers speakers.
Im surprised shield brings me back to the times 5 years earlier, i could hear it just now. Its random, but nothing i would be concerned of. Theres no point of rma this since its more of us noticing, i guess all the shield tablets produce this electric-static noise, speakers are pretty neat so maybe it was harder to hide imperfection of nvidias sound solution?
More accurate to confirm would be to know other tablets that use the same sound processor vs above mention hissing mechanical sound.
I can only hear it at night though, and frankly, it is loud but it still keeps me happy. My old oem pc was worse, it hissed even by moving the mouse around, it was so bad you could count dpi with closed eyes! Now that's what i call disturbing :laugh:
ErickZ5 said:
I too have noticed this on my lte unit first night use.
I might be talking about something else, although regarding the hissing noise similar to harddrive (i dont really get the popping noise, nowhere near loud PoP sounds)
I can relate this noise very similar experience ive had on my computer with low level (in anotherwords cheap) onboard sound card -chip. Board was made by intel for dell. Basically it did the very close, in moments when hdd&ram cooperated in that computer under high cpu load, this sound came from the computers speakers.
Im surprised shield brings me back to the times 5 years earlier, i could hear it just now. Its random, but nothing i would be concerned of. Theres no point of rma this since its more of us noticing, i guess all the shield tablets produce this electric-static noise, speakers are pretty neat so maybe it was harder to hide imperfection of nvidias sound solution?
More accurate to confirm would be to know other tablets that use the same sound processor vs above mention hissing mechanical sound.
I can only hear it at night though, and frankly, it is loud but it still keeps me happy. My old oem pc was worse, it hissed even by moving the mouse around, it was so bad you could count dpi with closed eyes! Now that's what i call disturbing :laugh:
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To me it sounds more like a voltage conversion-related sound like many power adapters make (including the Shield's) when under load. My power strip will also produce that sound if you plug high-power devices straight into its USB ports (I wish I knew the amperage on those ports).
EDIT: I have heard this sound on occasion myself is what I mean by this, and it doesn't sound like old "speaker squeaking" I've observed on older computers. I HAVE heard it on some laptops.
Thanks a lot for the feedback guys, i just wanted to know if there's something wrong with my tablet or it's something everyone gets. Anyway, i've also noticed some hissing when scrolling in Chrome. Not sure if it's the speakers or internal components hissing but it's not that big of a deal.