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Son of Where's that noise coming from

  [vote for,

Re-encountering the linked idea, I thought at first it would be for something else. But it wasn't. So this is.

Phones now generally have at least two microphones (for noise cancellation), and are full of complex gubbins. This should make it possible to build an app that tells you where a noise is coming from.

The app would listen to incoming sounds, and identify the main components (for example, sounds which recur periodically like a ticking clock; and the main pitch components of continuous sounds like a whistling or humming). It would then list these on screen and replay any one of them on request, so you could tell that, for instance "Sound number 3" is the low-pitched whistle that's annoying you.

The phone ought then to be able to tell you which direction that particular sound is coming from, based on phase differences between its two microphones.

(I'm getting deja vu all over again about this idea, so maybe it's been done...)

MaxwellBuchanan, May 27 2015

The idea that wasn't this one. Where_27s_20That_20Noise_20Coming_20From
[MaxwellBuchanan, May 27 2015]

Acoustic intensity http://www.google.c...4XETqSKA_xTXm6Xtv3w
Description of how to visualise sound fields [bhumphrys, May 27 2015]

Prior art... Pop-up_20Sprinkler_...d_20Laptop_20Camera
[normzone, May 27 2015]

http://en.wikipedia...iki/Gunfire_locator [hippo, May 28 2015]

Nifty, inappropriate http://io9.com/stud...-and-sou-1693561917
replacement for ear buds [4and20, May 29 2015]

Prior art Sound_20Source_20Locator
handheld hardware device with laser designator [notexactly, Nov 14 2015]

Prior art Audio-based_20Sniper_20Source_20Locator
helmet-mounted device for soldiers [notexactly, Nov 14 2015]

Prior art Find_20Snipers
fixed installation, noted to be double-pre-baked [notexactly, Nov 14 2015]

Prior art Sensound_ae
hardware device intended for blind people [notexactly, Nov 14 2015]

Directed Energy Precipitation Stimulation https://hackaday.io...itation-stimulation
And the thing I was on about last year. [notexactly, Feb 20 2016]

Prior art Noise triangulator
Just discovered [notexactly, Feb 26 2017]


       There was a famous Canadian novelist, half deaf, who went trekking down train tracks and was hit by a train he didn't hear. For everyone else I imagine that ears are better at localizing than apps.
4and20, May 27 2015

       How about "where's the noise of that coming from?" for when you bothered by noisy love making late at night and don't know who's doing it.
xenzag, May 27 2015

       Sound is a vector field. You can measure the dierction as well as the magnitude at any point in space, and by combining the output of a sound intensity probe with a pressure level map you can infer the origins of sound (see link).   

       Or Mike Murdock (Daredevil) can do it.
bhumphrys, May 27 2015

       Isn't sound (pressure) a scalar field? How do you measure the direction of a sound at a point in space?
EnochLives, May 27 2015

       Actually a cell phone might be better at locating some noises than human ears if they can detect higher frequencies.   

       I was in a house that wasn't mine and started hearing a fairly high pitched beep about once every minute, but the pitch and the fact that there was a long time between beeps made it incredibly difficult to find. We basically had to move around and try to figure out if it was louder this time or the previous time. It turned out to be the refrigerator warning us that the door was ajar.   

       This app should run continuously for a long time and add a new sound to the list whenever one is recorded.
scad mientist, May 27 2015

       //How do you measure the direction of a sound at a point in space?// You don't. Phones nowadays have two microphones.
MaxwellBuchanan, May 27 2015

       Well, given that phones these days have a dizzying array of inclinometers and accelerometers - you could probably get this thing to the point that you could speew the phone about say a vertical axis, and it could, by knowing the position and orientation of both microphones, determine fairly precisely the direction if not range of the noise source.
Custardguts, May 27 2015

       //You don't// unless you have a tube you can put the mic in.
FlyingToaster, May 27 2015

       I had an Aureal 3d sound card back in the day. It was incredibly good at reproducing sounds to create the effect of where they were coming from, using only stereo headphones. Sounds above and below you in the same vertical plane would theoretically arrive at your ears at the same time, but the quality and pitch were manipulated in such a way as to mimic the differences that allow us to tell when a sound is either directly above, ahead, behind, or below. This work they did should seem to have some application here.
RayfordSteele, May 27 2015

       I'm pretty sure this has been used to pinpoint the location of gunshots in cities - with microphones spread out over a city centre, you can, in theory, triangulate a gunshot sound (see link).
hippo, May 28 2015

       //everything’s perfectly unambiguous and should work first time no matter what technologies and processes [...]//   

       Thank you for the belly laugh, [Ian Tindale].
pertinax, May 28 2015

       ////You don't// unless you have a tube you can put the mic in.//   

       Perhaps when I mentioned that most phones have two microphones, I wasn't being clear enough. For clarity - most phones have microphones, and there are two of them. Two. One, and then another one. Like two cups of coffee, but with microphones.   

       Two microphones enable you (in theory) to tell the direction from which the sound is coming from, based either on relative sound intensities (iffy) or timing delays between the two mics.   

       If you are the fortunate possessor of a full set of ears (i.e., two; one plus one), you probably already know that you can estimate the direction from which a sound is coming. People with one ear have much more difficulty doing this. People with no ears cannot do it at all.   

       So, to clarify and eliminate any residual doubt - the idea depends on there being TWO microphones in most modern phones.   

       Further clarification available on request.
MaxwellBuchanan, May 28 2015

       I wonder how many ears the people who design these six-speaker systems expect us to have?
MaxwellBuchanan, May 28 2015

       [Enoch] yes the news that sound is a vector field amazed me too. But Brüel & Kjær, for example, offer training courses in the topic of sound intensity measurement and will also sell you an acoustic intensity probe and associated calibration equipment in order to be able to measure it.   

       At the position where it is set up, the probe measures the gradient of sound pressure in three directions, for example left-to right, back-to-front and up-and down. One technique of doing this is to set up three pairs of microphones, the microphones in each pair being very close together. The small distance between the microphones in each pair is known. Because the microphones are individual pressure sensors if you connect the electrical outputs together with opposite polarity the output represents the pressure difference between the two. This represents the 'gradient' of the pressure field in the direction along which the microphones are spaced. So with the six microphones,the gradient of pressure in all three directions is known. Together with the actual sound pressure level from the microphones, all the information about the sound field is then known.   

       The sound field at each point in space is the vector sum of the sound field from each emission source, or sink. Yes we've all heard of sound sources, but the idea of a sound sink is quite interesting isn't it?
bhumphrys, May 28 2015

       //So with the six microphones,the gradient of pressure in all three directions is known. Together with the actual sound pressure level from the microphones, all the information about the sound field is then known//   

       Is this sort of thing used for counter battery direction/ranging in artillery fire control?
bs0u0155, May 28 2015

       I can't see why not. But you would need to be careful not to fart near the microphone.
bhumphrys, May 28 2015

       // speew the phone about say a vertical axis,   

       Sounds unhygienic and/or physiologically impossible.   

       I think the gunfire location wotsit used in Northern Ireland was 'Ptarmigan', but I'll be buggered if can find any references to it..
not_morrison_rm, May 28 2015

       //the idea of a sound sink is quite interesting isn't it?// Interesting, but not surprising. I have taught students who absorb wisdom in much the same way that black hole absorbs light or a dog absorbs biscuits - i.e. with unlimited capacity but a complete inability to emit the absorbed item in any useful form.
MaxwellBuchanan, May 28 2015

       [Ian] I saw a demo at the BBC of some of the 2012 Olympics coverage in Super Hi-Vision with 22.2 sound - just amazing. They made the point that the technology was provided by NHK who did a similar demo of HD television at the 1984 Olympics.
hippo, May 29 2015

       <hiding to nothing>Super Hi-Vision with 22.2 sound </hiding> as whatever superscreen and/or sound system the makers create will most likely be publicised to the public on tv, on their own bog standard tv's.
not_morrison_rm, May 29 2015

       //counter battery direction/ranging in artillery fire control?//   

       Back in the 80s I think they used radar for that, not sound - anyone remember ArtHuR?   

       I'd guess that when you're trying to track down a howitzer, not a sniper, you probably don't have a line of sight to the source of the sound. Then, several miles of intervening objects might change the apparent direction of the sound - especially in an environment where there are many similar loud bangs. Radar, on the other hand, can get a line of sight to the projectile in flight, and then, so to speak, doodle a leisurely parabola on a sketch pad.   

       "I can tell you with some certainty it's coming fr [transmission interrupted]"
pertinax, May 29 2015



       They mostly have tall spires, ideal for placing microphones for triangulating sounds. Or Church-Net for that matter, as they also have line of sight of each other for microwave transmission. I hear the reception is divine, inspireing etc   

       Does make you wonder why the churches never bid for [whatever cellular telephony is called where your live] base stations..lack of aspireation?
not_morrison_rm, May 29 2015

       I've been thinking about this kind of thing for a while as a feature for my (nonexistent) smart glasses/headband. I never thought of it as a phone app, but I suppose that would be useful for people without said smart glasses/headbands.   

       To locate sounds in 3D, the phone will need one of the following:   

       1. Four or more microphones, not all in the same plane   

       2. Two (or maybe even just one) microphones, and knowledge of its phone-related transfer function(s)   

       3. To be moved/rotated as it listens with two microphones   

       All of those are achievable. I expect the app to be launched within the year.   

       // Isn't sound (pressure) a scalar field? How do you measure the direction of a sound at a point in space? //   

       Because sound has a finite speed. Look up microphone arrays, beamforming, particle velocity probes, etc.
notexactly, Jun 13 2015

       Generating beamformed audio is actually necessary for an idea I had recently, so thanks for the link. After looking at the datasheet, I think that part just might be suitable for my idea. I don't need any of the HRTF or stereo stuff though. I just need to produce the greatest sound pressure and/or particle displacement possible at 1–5 km range. (The array will be large. And no, this isn't going to be a sonic weapon.) I will try to remember post a link here when I post said idea.
notexactly, Jun 15 2015

       My prior art links are just for linking related ideas together, not to suggest that this should be deleted.
notexactly, Nov 14 2015

       Could be useful for my invisible animal syndrome, I can hear them, but they are behind a wall or something...or is it just me?
not_morrison_rm, Feb 26 2017


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