Detecting high pitched sounds

[rob_s]

I think we may have something on the house making high pitches sounds that are making the dog crazy. I’d like to be able to detect and locate the source, if any.

Is there an app or some kind of device I can use for this?

[Guerrero]

Some kind of spectrum analyzer app, like this (not affiliated with it):

https://play.google.com/store/apps/details?id=com.raspw.SpectrumAnalyze&hl=en_US

[Mjolnir]

[emoji242] [emoji193]?


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[OlongJohnson]

Invite a left-wing talking head over to the house? They seem to have zero problems hearing dog whistles.

/derailment

[CCT125US]

Some kind of spectrum analyzer app, like this (not affiliated with it):

https://play.google.com/store/apps/details?id=com.raspw.SpectrumAnalyze&hl=en_US

That's cool. Not sure what I will do with it, but that's cool.

[pistolwrench]

https://www.amazon.ca/Shomer-Tec-Nausea-Electronic-Disruption-Device/dp/B00ABV7OAM

[OlongJohnson]

That's cool. Not sure what I will do with it, but that's cool.

Take it to the range and analyze the spectra of different cartridges, loads, barrel lengths, cans, etc. Duh.

[HCountyGuy]

I think we may have something on the house making high pitches sounds that are making the dog crazy. I’d like to be able to detect and locate the source, if any.

Is there an app or some kind of device I can use for this?

Crazy how? Like batshit run all over the house crazy, barking at the door/staring outside or intently watching walls/ceilings?

[BN]

Do you have bats in the house?

[Peally]

Young people.

[SunTzu]

Is the dog inside or outside the house?

Bearing going out in fan motor of AC? Bugs or critters in the wall?

[Peally]

Bugs or critters in the wall?

A little more expensive than my "find a young person" solution (protip younger people can hear frequencies folks in their 20s+ can't) but it's still viable with enough money.

https://www.coolthings.com/wp-content/uploads/2017/01/hcg-aliens-m56-smartgun-1.jpg

[Guerrero]

A little more expensive than my "find a young person" solution (protip younger people can hear frequencies folks in their 20s+ can't) but it's still viable with enough money.

https://www.coolthings.com/wp-content/uploads/2017/01/hcg-aliens-m56-smartgun-1.jpg

I hope you're right. I really do, because just one of those things managed to wipe out my entire crew in less than 24 hours, now if rob_s has found that ship, there's no telling how many have been exposed. Do you understand?

[spinmove_]

I hope you're right. I really do, because just one of those things managed to wipe out my entire crew in less than 24 hours, now if rob_s has found that ship, there's no telling how many have been exposed. Do you understand?

Nuke the site from orbit. It’s the only way to be sure.


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[GMSweet]

If your dog is a really good indicator, start at the breaker box. My guess is the noise is coming from a noisy power supply, it's just a matter of finding out which one. Shut everything off and observe. If your dog is fine, then start bringing things back online until you find the breaker with the irritant and chase down everything on that breaker.

If nothing inside your own dwelling is causing the issue, do you live in an apartment or townhouse that shares common walls? With the rodent population explosion this year, is it might be possible that a neighbor purchased an ultrasonic repellent that isn't working properly. They are supposed to operate over the hearing range of pets, but we all know tolerance stacking can be a thing.

Matt

[rob_s]

It's a little tough to use the dog himself as the detector because he's otherwise deaf. He's also pretty old so he's acting weird anyway.

We had an issue with him running away several years ago and we tracked it down to (I think) one of my wife's camera battery chargers (she's a professional photographer) and once we unplugged that he stopped running away.

Lately he's been trying to get away again, which has me thinking it might be a similar issue.

[GMSweet]

He may still be a good sensor though. Is there a specific room in the house he won’t go into or stay in? I think you’re on the right track regarding things like chargers. See if you can track down anything new to the environmental since you noticed the change in your dog (I realize you likely did this already). After that, I would look at the oldest electronics in the room. I have heard squealing from old TV’s, monitors, chargers, and light ballasts (more humming than squealing).

Once you start looking at measuring equipment, you’re into fairly specialized stuff to have a microphone that can accurately read up to 60KHz and report on it including a digital sampler at 192KHz to get the Nyquist frequency above the dog’s hearing range.


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[Chance]

Some kind of spectrum analyzer app, like this (not affiliated with it):

https://play.google.com/store/apps/details?id=com.raspw.SpectrumAnalyze&hl=en_US

So if you're using something like this, what are you looking for? I'm convinced our ceiling fan is emitting a barely-audible squeal, but the wife insists she can't hear anything.

[Guerrero]

So if you're using something like this, what are you looking for? I'm convinced our ceiling fan is emitting a barely-audible squeal, but the wife insists she can't hear anything.

Human hearing is roughly in the 20 Hz to 20 kHz range. If you think you're hearing a "high pitched" noise, you could use it to see if it detects anything in the (for example) 15 kHz range.

[RJ]

Couple ideas.

If you have recently installed electronic dimmers, the circuitry may be oscillating due to the way the dimmer works. This oscillating generally is not well regulated, and has lots of square waves, which can and do generate harmonics of the original frequency. It's possible to have high frequency noise this way.

Same for fans, which are inductive loads. If the noise goes away when the fan is on high, you might have found the problem.

And of course the modern lamps themselves can also emit noises, or harmonics of noises.

An older power supply can emit noise, but these are usually at lower frequencies i.e. 60 Hz or harmonics. Usually people complain about "hum". Doesn't sound like your problem.

A spectrum analyzer app can work. I don't know what the frequency response of a smartphone is.

I just downloaded "Spectrum", a typical free app from the Apple store. It seems to indicate a coverage from base to north of 16K.

https://uploads.tapatalk-cdn.com/20181130/6717e6e5438aafab145b53ab9859f21d.jpg

The FFT size is 512 samples; and runs in real time (pretty amazing considering I used to program FFTs byte-wise using discrete circuitry in an, ah, Military Application back in the Dark Ages.) Whether the free version and iPhone is sufficiently sensitive to detect "high" frequency is probably dependant on what you are hearing, but might be worth a try.

A dedicated microphone / transducer, and some circuitry to buffer / sample it into a PC, with some either dedicated or roll your own software, will obviously cost more (sometimes a lot more.)

SoI guess I would try the easy stuff first (dimmers?) then look at a spectrum analyzer (free) and lastly maybe try the higher end stuff.

[RJ]

Once you start looking at measuring equipment, you’re into fairly specialized stuff to have a microphone that can accurately read up to 60KHz and report on it including a digital sampler at 192KHz to get the Nyquist frequency above the dog’s hearing range.



I'm not sure I've ever run into anyone online, let alone on pistol-forum, who knew what the Nyquist criteria was.

Very cool.

[peterb]

Bat detector? It is an ultrasonic -> audible frequency shifter.

https://www.echometertouch.com

[RJ]

Bat detector? It is an ultrasonic -> audible frequency shifter.

https://www.echometertouch.com

That is...pretty cool.

[GMSweet]

I'm not sure I've ever run into anyone online, let alone on pistol-forum, who knew what the Nyquist criteria was.

Very cool.

Years of being a bass player and home recording guy leads to awkward studies late in to the night. :cool:

It is one of the things I thoroughly enjoy about PF.com, I came for the pistols, and stayed for the rest of the conversations.

Matt

[Hambo]

Bat detector? It is an ultrasonic -> audible frequency shifter.

https://www.echometertouch.com

"Detector" is a misnomer. They convert the bat call into sound you can hear, but they don't detect them when they are roosting.

[rob_s]

SoI guess I would try the easy stuff first (dimmers?) then look at a spectrum analyzer (free) and lastly maybe try the higher end stuff.

I don't know that this is "easy" per se. In fact, it's kind of a nightmare proposition to go all around the house trying to figure out which switch or bulb might be the issue without some way to measure it.

I did download that app, and I tried it last night, but it's not exactly what I need.

[RJ]

I don't know that this is "easy" per se. In fact, it's kind of a nightmare proposition to go all around the house trying to figure out which switch or bulb might be the issue without some way to measure it.

I did download that app, and I tried it last night, but it's not exactly what I need.

It occurs to me maybe call a water leak-detection company?

I had them look for and find a small pin-hole leak in my house (couple of them) a few years back. They have fairly sensitive detection equipment that works off of the audio/sound emitted by leaks; could be their frequency range might cover high-freq noise you are hearing.

Worth a phone call perhaps.

[farscott]

Being as I like to start with simple things, my first step would be to look at any electronics that were changed or added. You can either kill whole circuits or remove loads one at a time and then observe the dog's behavior. The "wall warts" provided with many pieces of modern electronics are AC/DC power supplies made on the cheap. These often have transformer wiring that is not varnished or resin-coated (costs money), and the wire turns actually move at a subharmonic of the switching frequency (usually 80 kHz to 2.2 MHz) from the magnetic field. That is the main source of transformer hum, although I have also seen cores move within the transformer bobbins.

Other known problem products are dimmers (as mentioned above), CCFL and LED lights, ceiling fans (as mentioned above), cell phone chargers (LG is the worst), and any countertop appliance. Anything with a three-phase or permanent magnet motor can be a cause. For example, washing machines, dishwashers, or refrigerators that are advertised as "inverter" or "direct drive" usually switch at 16kHz as a compromise between acoustic noise (higher frequency is better) and switching losses (lower frequency is better). Older people, like me, cannot hear the switching. Young people and dogs can.

[Shoresy]

I'm not sure I've ever run into anyone online, let alone on pistol-forum, who knew what the Nyquist criteria was.

Very cool.

This place must be the twilight zone... my first job out of high school was writing algorithms for vibration analysis. FFTs and sample rates were right at the core of my work.

[Jaywalker]

I use DecibelX app on my iPhone to check road noise when checking out cars to buy. Can't say whether it would detect a high frequencies, because I can't hear high freqs anymore. If it does it would give you a graphical display of it, which might be helpful in localizing it.

[rob_s]

The issue I'm finding with the apps is that they are reporting across all frequencies, and it's hard to localize for just one.

What would be great is if the app let you only report on the highest frequencies.

I'm also not sure the iphone mic picks up the same frequencies that are making the dog crazy.

[RJ]

The issue I'm finding with the apps is that they are reporting across all frequencies, and it's hard to localize for just one.

What would be great is if the app let you only report on the highest frequencies.

I'm also not sure the iphone mic picks up the same frequencies that are making the dog crazy.

“Spectrum” at least will let you select a band, then it gives a dB value for that band.

16kHz in this screen shot:

https://uploads.tapatalk-cdn.com/20181205/6cba115d2f3e33a871e09e6f5b9d8d2c.jpg


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