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simonw 23 minutes ago [-]
I didn't mention this in the article, but this isn't the first time my family has been driven almost spare by a mysterious, hard-to-track beep.
Our dog goes outside and hides in the lavender bush if a smoke alarm starts making a "I need a battery" noise.
So I went into this project with the attitude that I would like to solve this class of problem forever.
tristanj 3 hours ago [-]
You can also solve this in O(logn) using a physical binary search:
1) Move half the boxes to another room.
2) Listen for a beep and determine which room the beep comes from.
3) Take the boxes in that room and split them in half again.
4) Repeat until one box is left.
aizk 1 hours ago [-]
It's O(logn) but you haven't accounted for how heavy each item in the array of n is.
kelseyfrog 12 minutes ago [-]
If you randomly index them and there's enough of them then on average the partitions average out.
mauvehaus 40 minutes ago [-]
This is true, but it probably isn't a box of books that's beeping.
I also feel like ordering the moves by lightest box first is reasonable as a real-world optimization.
tonyarkles 42 minutes ago [-]
Lol classic “ignore the constant factor” gotcha when using Big-O.
entropie 2 hours ago [-]
Or you could use a very heavy blanked to just cover some boxes to supress the sound enough to simulate moving boxes.
peri-cl 31 minutes ago [-]
Yes, but that's also O(log n) physical effort. This one's O(1) sitting on your butt.
(Out of curiosity: I think "physical binary search" is more properly O(n^{1/3} log(n)), or maybe O(n^{1/2} log(n)). Since physical objects have sizes, and moving things (or moving between things) takes time proportional to distance).
pyrolistical 23 minutes ago [-]
That requires you to stand in the room and listen for which side. So it’s nlogn times a very long time constant
ARandomerDude 3 hours ago [-]
> Move half the boxes to another room.
Alternatively, no.
malfist 1 hours ago [-]
Alternatively, you can unpack
1 hours ago [-]
solyin 2 hours ago [-]
MKBHD demos the the FOTRIC TD2e Acoustic Imaging Camera.
Oh, was gonna post a comment about this, I actually bought just last week their USBc version (Fotric Sonic 3), on eBay, for around $700. Works quite well, it has 64 mic array, I think it would be tough to replicate it to this level.
Lmk if anyone has any questions about it! It’s android-only, but I’ve gotten an agent to write a Mac version of it though haven’t tested yet.
Are you able to gather the multichannel recordings off the device? I’ve often wondered if you could do that, then replay a video while focusing on specific parts of the scene. Kind of like a virtual stethoscope.
ortusdux 2 hours ago [-]
Great thing for tool checkout/rental at a makerspace!
dangistan202611 45 minutes ago [-]
Does it work for infrequent sounds? The sound might for example come in the middle of the night for two seconds, loud enough to wake one up, then go away. If I leave it on, can it do continuous recording and max or threshold-based capture?
simonw 26 minutes ago [-]
That should work. You could always have Claude Code run the server itself and explain to it the rough parameters of the sound (two seconds, late at night) - then let it listen for hours and occasionally tweak its own configuration to try to better capture what's happening.
In my case it identified that the likely beep was about every 62 seconds pretty quickly - then I confirmed that one of the recordings was the mystery sound and it locked in from there.
raldi 2 hours ago [-]
WHAT WAS MAKING THE BEEP!!?!?!
gandreani 2 hours ago [-]
Hahahaha. You should slow down when you read
"The system worked as intended. It gave me the position of the beep to within about 40cm, then I dug through that specific pile of boxes and found an ancient carbon monoxide detector that desperately wanted its batteries replaced."
raldi 2 hours ago [-]
Oh, thanks. Not sure how I missed that in the very middle of the piece :D
Maybe I should have asked Claude to help triangulate it for me.
hk1337 1 hours ago [-]
I wonder if it would work to find an annoyatron?
adm4 2 hours ago [-]
wonderful! Thanks for sharing. I thought about doing this to track the sounds moving around in my stomach... it is interesting how well the mic on your smartphone works at picking up stomach sounds
Woah this is cool. Another interesting simonw project based around sound through browsers. Lots of simple real world problems that can be tackled with this.
hinkley 1 hours ago [-]
I had a beep that drove me crazy and the very long search turned up a surplus CO monitor that I didn’t recall buying and had gotten tucked into the laundry room for some reason.
Same brand as my smoke detectors.
Make sounds that can be detected directionally, assholes.
Our dog goes outside and hides in the lavender bush if a smoke alarm starts making a "I need a battery" noise.
So I went into this project with the attitude that I would like to solve this class of problem forever.
1) Move half the boxes to another room.
2) Listen for a beep and determine which room the beep comes from.
3) Take the boxes in that room and split them in half again.
4) Repeat until one box is left.
I also feel like ordering the moves by lightest box first is reasonable as a real-world optimization.
(Out of curiosity: I think "physical binary search" is more properly O(n^{1/3} log(n)), or maybe O(n^{1/2} log(n)). Since physical objects have sizes, and moving things (or moving between things) takes time proportional to distance).
Alternatively, no.
https://www.youtube.com/shorts/ai1gIWacf0I
It costs ~$1,000 so you'd probably rent it if you're only going to use it once, but it's a neat gadget.
https://www.minidsp.com/applications/usb-mic-array/acoustic-...
Lmk if anyone has any questions about it! It’s android-only, but I’ve gotten an agent to write a Mac version of it though haven’t tested yet.
eBay link to what I bought: https://www.ebay.com/itm/960060893216
In my case it identified that the likely beep was about every 62 seconds pretty quickly - then I confirmed that one of the recordings was the mystery sound and it locked in from there.
"The system worked as intended. It gave me the position of the beep to within about 40cm, then I dug through that specific pile of boxes and found an ancient carbon monoxide detector that desperately wanted its batteries replaced."
Maybe I should have asked Claude to help triangulate it for me.
Same brand as my smoke detectors.
Make sounds that can be detected directionally, assholes.
Who would win?? :-)
I lack the courage to plant such a PCB prank device... it really feels like you could drive people completely crazy haha