[piinbinary]

One day I want to build something like this, except for sound. It would be great to get a heading and distance for where a sound is coming from.

This could be both for small scale things (e.g. which part of this is squeaking?) or large scale (e.g. is that booming noise coming from the construction a few blocks away?)

[dfc]

Fluke has made an acoustic imager for a while now. It is used for detecting leaks:

https://www.fluke.com/en-us/product/industrial-imaging/fluke...

[geerlingguy]

There are a few knockoff options too, which are not quite as nicely calibrated, but get the job done for much less than Fluke-level prices. Like the FOTRIC TD2.

I think a few people have made homebrew versions too, like this one mentioned on HN: https://news.ycombinator.com/item?id=45137584

[m463]

interesting on amazon:

fluke $25k

flir $10k

td2 $1k

These are the kinds of things you look at and think - maybe I DO need night-vision, or a soldering iron with a cpu, or a thermal imager, or a steerable endoscope or now an acoustic imager....

[thomashabets2]

If you own your home I'd say you need a thermal imager. Just the ability to diagnose clogged pipes is priceless.

https://x.com/ThermoInstagram/status/909356506059026432

Also for checking if microwaved food is ready.

[greggsy]

+1 to thermal imager. I use mine to locate hot wires, heating and cooling gaps in the roof and around windows, car maintenance, the pizza oven, and its even sensitive enough to ‘see’ studs in the wall.

Priceless on one occasion for finding leaks in the ceiling, which are notoriously hard to pinpoint.

[m463]

> and its even sensitive enough to ‘see’ studs in the wall.

oooh my. My studfinder is always a little uncertain. I would love a second opinion.

[left-struck]

Can also be used for looking at heat leaking into or out of your house via conduction, which can help you determine where there might be more insulation needed, or maybe a particular wall needs more shade in summer.

[its_down_again]

Has anyone tried acoustic imaging for water leaks inside walls? I live in a multi-floor 1900s Victorian. A leak can affect several units, and tracing the source can mean opening walls or floors in multiple places, and coordinating access has been getting harder with less WFH.

Could one of these tools help map water pipe routes and trace a leak, or are they only going to be useful for air and gas leaks?

[iamniels]

For a water leak a sound imaging device is not going to help you.

You should definitely try a thermal camera. Any moisture will create small temperature differences which are easily picked up by a thermal camera.

[_trampeltier]

Flir has some thermal cameras with 'special moisture' modes. In the end, wet areas are just colder.

[cluckindan]

Moisture camera. Now there is an idea.

[fc417fc802]

Initially I scoffed, but then I recalled that certain RF bands are disproportionately absorbed by water and this is used for certain sorts of atmospheric imaging by satellites. So you'd need a moisture "light" and an RF camera. Other than being cost prohibitive it sounds like an awesome toy.

[archi42]

It still works pretty well in the IR band. I know that one from experience due to storm damage to our roof ;-)

A leak only turns invisible if the water has the exact same temperature as the wall and there is no meaningful evaporation happening (as that cools the affected area).

Of course don't let me stop you from actively probing your all using RF. Though also there you might have good chances with IR, since wet $stuff should behave differently than dry $stuff ;-)

[KaiserPro]

WArning I am not an expert

There is a man call leak detective, who hunts for leaks in the UK. one tool he has is shutting off the water and filling the pipes with gas and using either sound or gas detector to pin down leaks.

A lot of the time he just listens though.

[greggsy]

Up until the 90’s airline in flight entertainment use stethoscope style earphones. My dad used to steal them for his workshop as a way to hear for leaks in various parts.

Our ears and eyes are very high bandwidth sensors.

[mrtnmcc]

Realtime sound visualization was actually a project I did 20 years ago as a freshman and that (probably?) inspired me to build this AR app in QuadRF.

On balance, I would say this RF version was 200x harder.

[flutas]

Not sure if you've heard of them, but they're starting to come to market with this exact thing aside from distance detection and more on the "which part is squeaking" side.

https://www.youtube.com/watch?v=l8-5lSVCR2w

[cenamus]

I think you'll be very interested in this awesome project

https://ribbonfarm.com/2016/06/29/the-daredevil-camera/

[hinkley]

The army has one of these for sniper triangulation, and Boeing made a civilian version for optimizing sound dampening on the 787. I don’t know if they kept doing that on subsequent planes but I would expect so given how enthusiastic they were about being able to apply the weight budget to greater effect.

You need really high clock rate sensing to differentiate the arrival time for sound from microphone arrays where they are all less than a nanosecond separated from each other.

[azalemeth]

A nanosecond? The speed of sound at sea level in dry air is approximately 330m/s. So at say 3.3 kHz, the rough logarithmic middle of the audible spectrum, K=2π/lambda is 2π/0.1 m=20 π rad/m. A phase difference from a source difference k. ∆r would therefore likely be far more easily resolved than that for many physical ∆rs then, no?

[hinkley]

Whups. Sound not light.

Sensors around 12.5 inches apart will be a millisecond separated. The actual device was from a fuzzy recollection of a picture I saw, was probably 700 microseconds across. But it was a sphere with many sensor so adjacent sensors were less than .1 ms of separation. They would have all the time in the world to calibrate such a thing.

My guess is rather than triangulation, they probably just find the two microphones with the widest phase separarion between their signals and draw a line back between them. I don’t actually know how much 3D sonic math they’re doing.

What I do recall is that it was tech that had recently reached the Cheap Enough to Use status at the time, which is about 20 years ago now?

[KaiserPro]

MAybe the high clock rate it to allow it to read the output of the ADCs serially?

[a_paddy]

Given that it was McDonnell Douglas, sorry Boeing, they probably cut it.

[hinkley]

Why don’t you give me a paper cut and pour lemon juice into it?

[Torkel]

There are products in this space, eg https://www.crysound.com/

Very cool stuff, can be used for drone detection at up to 200m. Accuracy is not super good, unless you make mic spacing a bit large.

[wkjagt]

Steve Mould did a cool video on this: https://m.youtube.com/watch?v=QtMTvsi-4Hw

[KaiserPro]

respeaker and https://github.com/introlab/odas might be a good starting point without having to make hardware.

Making the hardware is fairly achievable without having to do fancy things. but if you want >8 channels you'll need to make some custom interface hardware.

[simplyalec]

I've seen http://soundryx.com/

[wyager]

There's a company in Austin that uses sound for drone localization, although I forget the name

[lowbloodsugar]

I want that but for smell.

[amelius]

Nobody can do that. Use dogs.

[NopIdoN]

You could try training wasps.

[tzs]

Like in this Steve Mould video, "Acoustic cameras can SEE sound" [1]?

[1] https://www.youtube.com/watch?v=QtMTvsi-4Hw

[tenuousemphasis]

You should visit Orfield Labs in Minnesota.

[piinbinary]

ChatGPT tells me that it would take a very large array to detect distance with any accuracy