Sound Source Detection 1

[magaler]

I'm living in a rented condo and there is often banging and music coming from somewhere. I'm trying to pinpoint where the sound waves are coming from, ie: exact locations near the door or other areas, so I can make attempts to block the waves or pinpoint the exact unit they're coming from.

I'm wondering if there are any simple devices that can be purchased in order to detect the actual direction and source of sound waves from the measured area? I'm willing to spend a few hundred dollars for such a device.

Any help is appreciated, thanks.

 

[GregLocock]

The answer is yes, to some extent it can be done very cheaply using acoustic intensity,

https://en.wikipedia.org/wiki/Acoustic_intensity,

in which a pair of microphones are used as a directional sensor, the delay between the two essentially identifying the sound power vector. But, room acoustics are largely reverberant, in which case there is no sound power flux, and you may find that treating an apparent source makes no difference to the sound pressure level in the room.

You'll need something to analsyse the signal with,

http://www.abravibe.com/toolbox.html

for example.

The microphones don't need to be very posh, they need to respond at the frequency of interest, but errors in phase and magnitude response can easily be calibrated out by swapping the two microphones over.

The rather more significant difficulty is that any effective sound treatment is likely to be inconvenient, expensive, or ineffective, often all 3.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[SomptingGuy]

Slightly OT, but here's a link to a commonly referenced B&K document about Sound Intensity and its measurement:

http://www.bksv.com/doc/TechnicalReview1982-3.pdf

It describes the popular two-microphone method very well. We've used an implementation of this for many years on engines to map the acoustic sources. Areas of the engine are marked out and swept individually. The sources can then be ranked. (Some areas often have negative intensity - the are ne absorbers).


- Steve

 

[magaler]

Very helpful information Greg & Steve, thanks very much I'm going to look into this.

 

[LiteYear]

FWIW, such devices are routinely deployed near coal mines so the source of noise can be pinpointed (and blame appropriately applied). I've seen three microphone versions that work quite well. Many mining engineering consultancies will know what you're after.