Forums

tracking sound source

Started by Sylvia July 15, 2007
Does any one know good material on tracking single sound source using only
two microphones on a dummy head.I have seen kalman filter tracking for
constant velocity targets etc in case of radar applications  but i dont
know how to use these in case of sound sources.
Thanks
"Sylvia" <sylvia.zakir@gmail.com> wrote in message 
news:uLOdnfVcWq6GhQfbnZ2dnUVZ_u6rnZ2d@giganews.com...
> Does any one know good material on tracking single sound source using only > two microphones on a dummy head.I have seen kalman filter tracking for > constant velocity targets etc in case of radar applications but i dont > know how to use these in case of sound sources. > Thanks
Unless you know the sound amplitude of the source, you won't be able to get range information. With only two microphones, you can use beamforming or interfrometry techniques to detrmine the position of the source as somewhere on a cone. In the 2 dimensional case this reduces to 2 lines that cross the line between the sensors at the same point. If, as is usually the case, the source is far from the two microphones compared to the separation of the microphones, you will have localized the source to two lines that cross the line formed by the microphones at a known angle. Usually, you assume that the source is on one side of the sensor. With these assumptions, you have a series of angles to the sensor. Google "alpha beta tracker" or "alpha beta gamma tracker" for ways of predicting the source's future position. Best wishes, --Phil Martel
On Sun, 15 Jul 2007 11:19:31 -0400, "Philip Martel"
<pomartel@comcast.net> wrote:

> >"Sylvia" <sylvia.zakir@gmail.com> wrote in message >news:uLOdnfVcWq6GhQfbnZ2dnUVZ_u6rnZ2d@giganews.com... >> Does any one know good material on tracking single sound source using only >> two microphones on a dummy head.I have seen kalman filter tracking for >> constant velocity targets etc in case of radar applications but i dont >> know how to use these in case of sound sources. >> Thanks > >Unless you know the sound amplitude of the source, you won't be able to get >range information. With only two microphones, you can use beamforming or >interfrometry techniques to detrmine the position of the source as somewhere >on a cone. In the 2 dimensional case this reduces to 2 lines that cross the >line between the sensors at the same point. If, as is usually the case, the >source is far from the two microphones compared to the separation of the >microphones, you will have localized the source to two lines that cross the >line formed by the microphones at a known angle. Usually, you assume that >the source is on one side of the sensor. > >With these assumptions, you have a series of angles to the sensor. Google >"alpha beta tracker" or "alpha beta gamma tracker" for ways of predicting >the source's future position. > > Best wishes, > --Phil Martel
Believe it or not, you can get range with a single microphone *with some qualifying assumptions*. Basically, if the target is travelling in a straight line the doppler characteristic can be used to determine range once the target approaches close to (but even a little before) the point where it is closest to the microphone. Eric Jacobsen Minister of Algorithms Abineau Communications http://www.ericjacobsen.org
"Eric Jacobsen" <eric.jacobsen@ieee.org> wrote in message 
news:cfmk93t3lkb3de6tsjj24ots2usdnjnp9o@4ax.com...
> On Sun, 15 Jul 2007 11:19:31 -0400, "Philip Martel" > <pomartel@comcast.net> wrote: > >> >>"Sylvia" <sylvia.zakir@gmail.com> wrote in message >>news:uLOdnfVcWq6GhQfbnZ2dnUVZ_u6rnZ2d@giganews.com... >>> Does any one know good material on tracking single sound source using >>> only >>> two microphones on a dummy head.I have seen kalman filter tracking for >>> constant velocity targets etc in case of radar applications but i dont >>> know how to use these in case of sound sources. >>> Thanks >> >>Unless you know the sound amplitude of the source, you won't be able to >>get >>range information. With only two microphones, you can use beamforming or >>interfrometry techniques to detrmine the position of the source as >>somewhere >>on a cone. In the 2 dimensional case this reduces to 2 lines that cross >>the >>line between the sensors at the same point. If, as is usually the case, >>the >>source is far from the two microphones compared to the separation of the >>microphones, you will have localized the source to two lines that cross >>the >>line formed by the microphones at a known angle. Usually, you assume that >>the source is on one side of the sensor. >> >>With these assumptions, you have a series of angles to the sensor. Google >>"alpha beta tracker" or "alpha beta gamma tracker" for ways of predicting >>the source's future position. >> >> Best wishes, >> --Phil Martel > > Believe it or not, you can get range with a single microphone *with > some qualifying assumptions*. Basically, if the target is travelling > in a straight line the doppler characteristic can be used to determine > range once the target approaches close to (but even a little before) > the point where it is closest to the microphone. > > Eric Jacobsen > Minister of Algorithms > Abineau Communications > http://www.ericjacobsen.org
Well, given a fixed frequency sound source (helicopter for exemple) I suppose you're right, though I'd have to think about it for a while to convince myself that the shape of the doppeler curve before CPA and the bearing rate would be enough to determine a unique range.
On 15 Jul, 22:28, "Philip Martel" <pomar...@comcast.net> wrote:
> "Eric Jacobsen" <eric.jacob...@ieee.org> wrote in message > > news:cfmk93t3lkb3de6tsjj24ots2usdnjnp9o@4ax.com... > > > > > > > On Sun, 15 Jul 2007 11:19:31 -0400, "Philip Martel" > > <pomar...@comcast.net> wrote: > > >>"Sylvia" <sylvia.za...@gmail.com> wrote in message > >>news:uLOdnfVcWq6GhQfbnZ2dnUVZ_u6rnZ2d@giganews.com... > >>> Does any one know good material on tracking single sound source using > >>> only > >>> two microphones on a dummy head.I have seen kalman filter tracking for > >>> constant velocity targets etc in case of radar applications but i dont > >>> know how to use these in case of sound sources. > >>> Thanks > > >>Unless you know the sound amplitude of the source, you won't be able to > >>get > >>range information. With only two microphones, you can use beamforming or > >>interfrometry techniques to detrmine the position of the source as > >>somewhere > >>on a cone. In the 2 dimensional case this reduces to 2 lines that cross > >>the > >>line between the sensors at the same point. If, as is usually the case, > >>the > >>source is far from the two microphones compared to the separation of the > >>microphones, you will have localized the source to two lines that cross > >>the > >>line formed by the microphones at a known angle. Usually, you assume that > >>the source is on one side of the sensor. > > >>With these assumptions, you have a series of angles to the sensor. Google > >>"alpha beta tracker" or "alpha beta gamma tracker" for ways of predicting > >>the source's future position. > > >> Best wishes, > >> --Phil Martel > > > Believe it or not, you can get range with a single microphone *with > > some qualifying assumptions*. Basically, if the target is travelling > > in a straight line the doppler characteristic can be used to determine > > range once the target approaches close to (but even a little before) > > the point where it is closest to the microphone. > > > Eric Jacobsen > > Minister of Algorithms > > Abineau Communications > >http://www.ericjacobsen.org > > Well, given a fixed frequency sound source (helicopter for exemple) I > suppose you're right, though I'd have to think about it for a while to > convince myself that the shape of the doppeler curve before CPA and the > bearing rate would be enough to determine a unique range
You can't fix the range that way, only get a time for the CPA. You'll need at least two mics to geat a bearing to CPA. In order to fix a range with only one mic, you will need *knowledge* of the type of helicopter. If you *know* the make and model of the helicopter, you also *know* certain key characteristics in the sound signature, and can use those to estimate the speed and range based on the Doppler characteristics. Provided, of course, that the pilot plays your game and flies at constant speed in a straight line. Once you do no longer *know* the characteristics, but have to *estimate* them, with all the uncertainty that follows, all bets are off what ranges and speed are concerned -- again, with only one mic involved. If you have an array where you can track bearings, things become somewhat easier. Rune
On Jul 15, 5:50 am, "Sylvia" <sylvia.za...@gmail.com> wrote:
> Does any one know good material on tracking single sound source using only > two microphones on a dummy head.I have seen kalman filter tracking for > constant velocity targets etc in case of radar applications but i dont > know how to use these in case of sound sources. > Thanks
Sylvia Is 'dummy head' a necessary part of the problem statement? If your question is about modeling the human head then look for HRTF: head related transfer function. If your question is about tracking sound sources with two sensors, there are a number of possibilities. If your problem can be defined to allow you to determine bearing, such a operating in a half-plane containing the sensors and using time delay to determine bearing, there is a considerable literature on "bearings only trackers". Some of this literature was developed to support the sonobuoy community where collocated directional and omni sensors are used to resolve bearing ambiguity. Some of these algorithms require multiple sensor locations. Look in IEEE Transactions on AES. In the special case of a source at a constant frequency traveling in a straight line at a constant velocity, a single sensor allows calculation of velocity from the maximum doppler deviation at long range and range of CPA from the doppler slope at CPA. A second sensor allows bearing calculation. Look in Journal of the Acoustic Society of America (JASA) for examples of acoustically tracking aircraft. If you are interested in applications for tracking human voice then the simplifying assumption of a single constant frequency is unlikely to be satisfied. Indoor applications will also be complicated by reverberation. So what are you really looking for? As always at comp.dsp, a more detailed question increases the chance of a relevant response. Dale B. Dalrymple http://dbdimages.com
On 16 Jul, 02:28, dbd <d...@ieee.org> wrote:

> Look in Journal of the Acoustic Society of America (JASA) for examples > of acoustically tracking aircraft.
The key word here is "aircraft." The other scenario where passive acoustic tracking is relevant is underwater acoustics. JASA has a history of letting weird underwater stuff through, so be very careful. If you find an article which cites the paper Collins & Kuperman: "Focalization: Environmental focusing and source localization", JASA, vol 90, p 1410 - 1422, 1991. be very, very careful about how you proceed. The authors of that paper claim that they are able to find the range to a source in an "unknown or partially unknown" environment. It's been some time since I last read that paper, but I never understood how the techniques worked. The way I interpreted the article, they had done a computer simulation to generate "measured" data and then run a computer program again to find the input parameters which replicated the "measured" data. There was, as far as I could tell, no records of blind -- let alone double blind -- tests or verifications, so I had no choise but to assume that the same person who generated the "measured" data also set up the "inverse" experiment. If that's correct, the paper is worthless as the "analyst" knows what results the experiment ought to produce, and so can stop the computations when the results are "good". Nevertheless, five years ago it was cited some 80 times by other articles. So just be careful. JASA might look impressive but not everything in there is quite up to expectations. Rune
On Jul 15, 6:05 pm, Rune Allnor <all...@tele.ntnu.no> wrote:
> On 16 Jul, 02:28, dbd <d...@ieee.org> wrote: > > > Look in Journal of the Acoustic Society of America (JASA) for examples > > of acoustically tracking aircraft. > > The key word here is "aircraft." The other scenario where > passive acoustic tracking is relevant is underwater acoustics. > JASA has a history of letting weird underwater stuff through, > so be very careful. > > If you find an article which cites the paper > > Collins & Kuperman: "Focalization: Environmental focusing > and source localization", JASA, vol 90, p 1410 - 1422, > 1991. > > be very, very careful about how you proceed. The authors > of that paper claim that they are able to find the range > to a source in an "unknown or partially unknown" environment. > > It's been some time since I last read that paper, but I > never understood how the techniques worked. The way I > interpreted the article, they had done a computer > simulation to generate "measured" data and then run > a computer program again to find the input parameters > which replicated the "measured" data. There was, as far > as I could tell, no records of blind -- let alone double > blind -- tests or verifications, so I had no choise but > to assume that the same person who generated the "measured" > data also set up the "inverse" experiment. If that's correct, > the paper is worthless as the "analyst" knows what > results the experiment ought to produce, and so can > stop the computations when the results are "good". > Nevertheless, five years ago it was cited some 80 times > by other articles. > > So just be careful. JASA might look impressive but > not everything in there is quite up to expectations. > > Rune
When reading any journal (or newsgroup) it is always necessary to carefully consider claims made and methods followed. I am sorry to hear that this has lead you to disappointment with an article in JASA. I have had that happen more than once, too. Since I have never felt adequately motivated to study all of the intricate details of the myriad match field processing algorithms that have been proposed, I have not read and do not intend to read this article in detail. From the abstract, introduction and conclusions it appears that Collins and Kuperman have proposed yet another MFP algorithm, listed their suggested approaches to implementation and claimed that it is feasible to try the algorithm on real data. They have made no performance claims. I am sorry this disappoints you. If others have gone on to actually perform some of the implementations suggested it is only appropriate for them to cite the source. Have you looked to see if any the citations are from people who have actually performed the additional tests you feel are important? Did any of them even work? In any event, most on comp.dsp are protected from this particular article by its specialization and with your warning the OP is now safe. Thank you, Dale B. Dalrymple
There was a recent article (last two or three years) by Yakov Bar Shalom, et 
al in one of the IEE transactions, perhaps the Transactions on Signal 
Processing, which covered 3-D tracking with two sensors.

In article <1184554366.199112.114630@o11g2000prd.googlegroups.com>, dbd 
<dbd@ieee.org> wrote:
>On Jul 15, 6:05 pm, Rune Allnor <all...@tele.ntnu.no> wrote: >> On 16 Jul, 02:28, dbd <d...@ieee.org> wrote: >> >> > Look in Journal of the Acoustic Society of America (JASA) for examples >> > of acoustically tracking aircraft. >> >> The key word here is "aircraft." The other scenario where >> passive acoustic tracking is relevant is underwater acoustics. >> JASA has a history of letting weird underwater stuff through, >> so be very careful. >> >> If you find an article which cites the paper >> >> Collins & Kuperman: "Focalization: Environmental focusing >> and source localization", JASA, vol 90, p 1410 - 1422, >> 1991. >> >> be very, very careful about how you proceed. The authors >> of that paper claim that they are able to find the range >> to a source in an "unknown or partially unknown" environment. >> >> It's been some time since I last read that paper, but I >> never understood how the techniques worked. The way I >> interpreted the article, they had done a computer >> simulation to generate "measured" data and then run >> a computer program again to find the input parameters >> which replicated the "measured" data. There was, as far >> as I could tell, no records of blind -- let alone double >> blind -- tests or verifications, so I had no choise but >> to assume that the same person who generated the "measured" >> data also set up the "inverse" experiment. If that's correct, >> the paper is worthless as the "analyst" knows what >> results the experiment ought to produce, and so can >> stop the computations when the results are "good". >> Nevertheless, five years ago it was cited some 80 times >> by other articles. >> >> So just be careful. JASA might look impressive but >> not everything in there is quite up to expectations. >> >> Rune > >When reading any journal (or newsgroup) it is always necessary to >carefully consider claims made and methods followed. I am sorry to >hear that this has lead you to disappointment with an article in JASA. >I have had that happen more than once, too. Since I have never felt >adequately motivated to study all of the intricate details of the >myriad match field processing algorithms that have been proposed, I >have not read and do not intend to read this article in detail. From >the abstract, introduction and conclusions it appears that Collins and >Kuperman have proposed yet another MFP algorithm, listed their >suggested approaches to implementation and claimed that it is feasible >to try the algorithm on real data. They have made no performance >claims. I am sorry this disappoints you. If others have gone on to >actually perform some of the implementations suggested it is only >appropriate for them to cite the source. Have you looked to see if any >the citations are from people who have actually performed the >additional tests you feel are important? Did any of them even work? In >any event, most on comp.dsp are protected from this particular article >by its specialization and with your warning the OP is now safe. > >Thank you, > >Dale B. Dalrymple >
On Jul 15, 9:22 pm, John_W_Her...@yahoo.com (John Herman) wrote:
> There was a recent article (last two or three years) by Yakov Bar Shalom, et > al in one of the IEE transactions, perhaps the Transactions on Signal > Processing, which covered 3-D tracking with two sensors. >
I suspect you mean Yaakov Bar-Shalom who is a frequent author in IEEE publications. Most of his tracking work appears in the IEEE Transactions on AES. He is also a frequent contributer to the IEEE Transactions on Signal Processing and sometimes the Proceedings of the IEEE. I make a point of updating the spelling because it makes a big difference on some simple search engines like the ones on the IEEE Xplore site. Dale B. Dalrymple http://dbdimages.com