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you could try to hear "bats" echo location sounds. Also we used something like this to detect leaks in a vacuum cover used for bonding materials together.

6:33 Yes, clipping distortion produces additional harmonics, so instead of a single pure frequency you'll get a bunch of additional frequencies. If those harmonics are above the sample rate (192kHz in your case) then they will reflect back and be reproduced as lower frequencies, which is called aliasing. Dan Worrall has made several incredible videos on this topic on his own channel and for FabFilter. His video called 'Samplerates: the higher the better, right?' on FabFilter's channel is a good one to start with, but all of his videos are amazing.

The old TV remotes used an ultrasonic 'click' to change channels and volume. You could shake your keys in front of the receiver port and if you had a combination of brass and aluminum keys they would change channels.

Back around 1985 I found schematics in Popular Electronics for an ultrasonic device to use in conjunction with the siren of a burglar alarm and it stated that it would disorient intruders, but also had warnings like keeping it away from pregnant women. So I had to build it. It used 4 super tweeters, which I had to order, and I had everything else in my shop. The circuit incorporated power transistors on heat sinks to drive the super tweeters, and analog ICs controlled by 3 pots to adjust sound frequency, amount of warble, and frequency of warble. The first time I powered it up, my brother had brought home subs for dinner, and the aluminum foil from the subs was laying on the table and it started moving across the table as if by magic, just from the ultasonic waves. When I aimed the tweeters at my brother, he immediately got a headache. We experimented and found adjusting the frequency to just out of human range, and then adding the warble so the frequency would cycle between just above audible to just below would create the most annoying effect. I'd get a headache just from indirect exposure. I had some annoying neighbors who would hang out and drink at the sidewalk after the bars closed, so I set it up on one of my front window sills aiming at the sidewalk and powered it through an X10 module so I could turn it on remotely, and the few times I tried it, the annoying neighbors went into their homes almost immediately. I have recently used it on my neighbor's neglected dogs to make them stop barking, and I found it made them immediately want to go in the house, obviously to get away from the sound. That was much better than pounding on the neighbor's door at 3am. I just hope they peed all over her house.

I used to hear those ultrasonic dog anti-barking devices as a kid (even went off with speaking…) and no adults could. The thing drove me NUTS. Hearing that back (after writing this comment originally) really brought back those memories…

When my father lived in his old house he used to have one of those rodent repellent devices. He had to get a more expensive one, because while the cheap one worked, I could hear it and it pissed me off. It's frequency wasn't that high, maybe around 19 to 22 kilohertz.

Also, the "cold" humidifiers used to add moisture to the air work by atomizing water into minuscule droplets using an ultrasonic transducer.

I still gotta watch the video through, but lately, I’ve been more mindful of the harmful effects that electronic high pitched noises cause. Even if you can’t hear it without putting your ear to it… I feel like it caused the Tinnitus I have now. I would love to hear more tech KZfaqrs bring attention to this when reviewing products. Companies really shouldn’t skimp on high quality power delivery in their products.. but SO many products get it wrong. Point being, it’s awesome to know that this microphone exists. Gonna watch the video now. 😂

You're correct. There are lots of aliasing issues. Aliasing is a very complicated subject. Thick books could ( and have been) written about it. The TLDR version is this: 1) There is no direct correlation between harmonics and aliasing, other than the fact that that distortion (overdriving the input) can generate harmonics that, in turn, cause aliasing. 2) It's important to understand how the Nyquist Theorem works. It basically says that the sample frequency MUST be at least twice the audio frequency you want to record. This means that your 192kHz audio interface can record audio frequencie at a maximum of 96kHz. If you record frquencies higher than this, there will be frquencies LOWER than 96kHz generated. This is the same phenomenon that makes a cartwheel appear to rotate backwards on film. If a spoke moves more than a full turn of the wheel between frames, it appears to move backwards. THIS is aliasing! 3) I don't know what audio interface you used, but unless it was a professional highend ($3000 range) it isn't suitable for recording in 192kHz. It doesn't matter what the maufacturer says. Manufacturing anti-aliasing filters that can handle such frequencies is still very expensive! In low cost interfaces, it's just a selling scam. They're of very low quality. 4) If you look at about 9:00 in your video, you see a number of thin lines, above the thicker audio line, going in the opposite direction. These are mirrored aliasing frequencies. They need not be above the audio frequency, they can also appear below it in the audio spectrum (remember the cartwheel above?) 5) I highly suspect that the audio you hear in the last device are such aliasing artifacts, that has been mirrored down into the audible spectrum. It's correct pobably that the device sweeps between 22 and 50 kHz. But the anti-aliasing filtering is of very poor quality (design). If you want to redo the test, and get propper results, I suggest that you beg, steal or borrow a professional interface with high quality AD converters.

It's a good idea to record the sound of a bat screaming, the noise of a stun gun, the sound of a monitor, and other interesting things.

the sound the 'stop barking' device made (slowed 80%) really reminded me of a BAD BRAKES on a crappy car... there is a PART on brake pads called a 'tell-tale' that purposely grinds against the disc to make that noise to PURPOSELYT GET YOUR ATTENTION to basically say "YOUR BRAKES ARE FAILING!! YOU NEED TO PUT NEW PADS ON OR YOU ARE GOING TO DIE!!!" lol - pretty darn cool Joe

You know you're getting old when 10:44 is completely silent and then he goes on to say "As you can hear..."

Years ago a repair friend of mine had ultrasonic unit he was repairing, it was used in the oil field for I forget what. It would pick ultrasonic sound and then hetrodyne it down to the audible range. What we discovered was when you take out your key chain with several keys and shake it, it is noisy as all heck! Solved the question of why the dog always knows when you pick your keys. Try it.

omg LOL that 'stop barking' device (when slowed 80%) just FREAKED OUT my cat LIKE CRAZY!!!! lol - She thinks it was something out side, so she ran over to the window and started growling!! LOL - YES, my CAT is GROWLING LMAO!!!!

Would be interesting to hear actual dogs and cats sounds pitched down for us to hear how much of their expression we are eventually missing out.

The cool thing about you is that when you add a random video related to the topic and give its origin like how you found it it's really rare to see people actually credit all the things they do in a video I always thought that someone should do that so thanks

I built an ultrasonic converter out of an old Zenith Space Commander TV remote control pickup years ago. I remember using it to listen to a squeaky hinge on a door.

I have a TASCAM Portable Recorder. When I record nature sounds the Bird song sounds completely different when I play back the recording. This microphone looks like a great solution to to the problem of recording the great outdoors. Thanks for the intelligent demonstration. Keep up the good work.

When I had an audiologist test my hearing, I was shown to be very sensitive to high-pitch noises (in the human hearing range, of course). That's probably why the bare-bones rodent repeller audio that you could actually hear was so loud and annoying to me. Now I know why dogs and cats react so strongly to ultrasonic noises; they literally hurt when they get to the top of the hearing range!

Could you pitch down bird chirps and other bird noises? Since house cats meows sound exactly like pitched up tiger sounds, birds could give us a look at what dinosaurs might have sounded like. Also other small animal noises. Like bee bumps or rat "laugh"? Also an ultrasound imaging machine?

Try using a CRT Computer monitor. Since CRT _TVs_ make a ~15khz sound when in operation (which is the TV's horizontal deflection frequency, actually audible by many people) it would be interesting to see if a CRT computer monitor would make an ultrasonic noise. Since those have a horizontal deflection frequency between 30khz and 130khz (depending on the resolution and refresh rate) those monitors would also probably get picked up by this microphone.

By using this microphone, I can have an idea what my cat is hearing 🐈

Very interesting video. Thanks for the work you put into it! (How about an ultrasonic cleaner and one of those electronic distance sensors, like some cars use to detect curbs?)

In the past I’ve used an ultrasonic microphone to detect minute high pressure gas leaks. Try releasing the pressure through a tire valve and see if it’s considerably enhanced with the microphone. It’s similar to how a Doppler can hear blood leakages in heart valves.

Thanks for the warning.

Very interesting! I've wondered what these sound like for decades. Thanks

Amazing video, I have always been fascinated by these frequencies and made some tests myself in the past by finding my and my family's hearing frequency limit. Everything you explained is very detailed and consistent, congratulations!

i expect this type of videos in future ❤❤❤❤

Throughout the video, there was only one thought that never left my mind, and which I found to be absolutely terrifying. Imagine if you were using this microphone trying to record ultrasonic sounds, and when you actually lower the frequency, you hear a human whisper/voice.

This video is so interesting, i would love to see more like this one, it's the first time I have seen anything about those type of microphone, and learning about those very specific products that nobody is talking about is very interesting

Thanks for introducing me to this mic! I honestly didn’t find much of the content interesting except the pitched down vocals which sounds amazing. I think you can figure out even more intriguing experiments with the mic. Looking forward.

With the electronic dog whistles (anti-bark devices) you had one 25kHz line and one 50kHz line. The second one was probably just the echo combined with the original wave. I think that because it seems half as intense as the first one and is exactly double the frequency.

You want something ultrasonic, try finding a really old TV with an ultra sonic remote control. Before infra-red was cheap/viable ultra sonic was used and it worked well, except for one little problem... If you jangle a bunch of keys or coins you could often get the TV to respond by changing channels or turning off because they produce ultrasound frequency noise!

We may not be able to hear sounds higher than 20Khz (or 17 or 15) but if they are loud enough they can be felt as a sort of pressure on the ears (I studied acoustics long ago). If you could test something with a CRT display like an old TV of monitor I'd like to see that. I'm sure some of them produced sounds outside the range of human hearing. You could also try measuring the sound of anything with a motor.

I didn’t expect to enjoy this video as much as I did! It was super cool to get an idea of the noise we can’t hear with our own ears!

With the 80% pitch reduction on the metal dog whistle, it sounds so similar to what i hear when people use dog whistles near me

Maybe you can make a part two of this where you will record sounds from different objects (like hitting two small things together) or devices like power supplies

This channel never ceases to amaze me. Awesome!

Common ultrasound devices: 1 some cars have ultrasound sensors on the side and rear to sense distance when backing in. 2 new style fog fountains and humidifiers use it to break up water droplets 3 bats in caves would be very cool 4 dolphins and sea life 5 old robbi the robot and his controller used it 6 many radio like devices have them internally in filter circuits and they may actually be auditable if the mic is near the circuitry. 7 some really old remotes used it. 8 distance measurement devices for robotics 9 some alarm systems use it.

11:30 That is clearly a defective sound disc producer, bad soldering, etc.; try to kick it with your hand; sometimes lenticular discs that vibrates to produce high frecuencies get stuck and do not work well and produce lower frecuencies because they can not vibrate at designed frecuency.

8:40 Whoah. That's really weird. There's a supermarket near me that has an Anti-Rodent noise maker and no one believes me that I can hear it. This graph shows what I'm hearing too. I obviously don't hear the full range, but it does get higher pitch, then (I hear) a click and it drops back down and repeats.

Your content is so unique! I just surf around your existing content to find interesting stuff.

There are ultrasonic speaker extensions out there meant for the most serious of audiophile community that I think would be pretty interesting to give a look at - the source would have to be something analog or extremely high res tho

It just makes sense that using a mic with 5x the range would sound better when the audio is "squished down" like that, but to actually hear them side by side kind of blew my mind. Before hearing them I vastly underestimated just how different they'd sound. I was guessing there'd be some technical difference that would definitely be audible, but that it'd be the kind of difference that would only really be meaningful to a director or extremely purist audiophile, but that wasn't the case at all. That was like the difference between $5 gas station earbuds and $120 studio headphones. Man, that's so cool. I've never seen anything quite like this before.

About 40-45 years ago we used a device that 'changed' ultra sonic sound into audible sound. It was used to detect leaks in a pneumatic system. So air leaks in tubes/pipes produces high pitch sounds.

Frequency oscillation that bottoms at human hearing range but then goes out of it is actually a great way to imagine how sounds that we can't physically hear would actually sound! Because the sound changes gradually, and when you've listened to the 85% lowered version, you now understand the full pattern, and you can continue the original higher pitch version in your mind even when the signal sounds quieter or dead silent. Basically our brains can "hear" these frequencies, but our hearing system just isn't tuned to provide these signals. But with this test we can actually hear them internally! Pretty cool.

Love this. Also glad you addressed aliasing and harmonics. About 2 years ago i bought a 5 pack of those electronic bug deterrent things because we had tons of spiders in our apartment. I was totally doubtful but I heard they actually work. I was completely amazed. They truly did work! we didn't see hardly any spiders for the whole next 12 months that we lived there. Was really nice to see the slow ultrasonic sweep on the first device you tested.

Great video. BTW, there is extensive, peer-reviewed research that we not only hear much higher than 20 kHz, but that we are also extremely phase sensitive up though 40 kHz or above. Some combinations of tone plus overtones extend to over 100 kHz. Finally, many musical instruments generate overtones up through 40 kHz and beyond.

I can actually hear the rodent repeler thing naturally. (Not sure if it's for rodents or mosquitoes). A house where I used to live has one of those things in the open garage area and every time I pass by that house walking, I have to cover my ears because the sound is piercing. It makes a constant slope (up and down) like an ambulance but with a very high frequency that the average human cannot hear. None of my friend's nor family members can hear it. I guess I have super hearing.

I'm fascinated by what they hear

I’ve been looking for this for a long time.

I am reminded of a device marketed to small retail businesses to get rid of/prevent loitering by teenagers. It emitted an alternating tone above the range of adult hearing, but low enough that teens could hear it. A video showed teens becoming agitated and deciding to leave when it was switched on, and they seemed unaware it was a noise causing their discomfort. What a great invention!

lol lol That was so so cool to listen to!! thanks buddy!!

from what I've heard, mice will go selectively deaf if only one frequency is played near them, so it's meant to sweep to avoid that. My best guess about the low frequency mouse scarer is that it's designed for a different power voltage or frequency. aldi sold knife sharpeners here in australia that were apparently designed for a lower voltage, and spun way faster than they should have to sharpen knives.

This is actually very cool idea

Great audio-geekery 👏👏

We actually tested this in an unscientific way in my high school electronics class. We connected a small speaker to a wave form generator and slowly cranked the frequency and had people hold up their hands until they couldn't hear it anymore. IIRC my hearing at the time topped out around 22~23K, which didn't surprise me. As a kid I used to hear CRT TVs and A/C systems that make weird high pitch sounds just after they shut off... Probably can't these days as I'm 40 now and I used to listen to very loud music in my teens and 20s. I concede that I didn't realize at the time we may have went beyond the frequency capabilities of the speaker itself, and we did not use a high end tweeter to do the test.

Really cool video, gj.

personally I love the way you conduct and present your research, so all of your content has been interesting to me. This particular topic is unique as far as content I've stumbled across on KZfaq, or even television for that matter. I like the fact that you didn't take us to deep into the Weeds. anymore on that particular type of device and I feel like I would be watching a orientation video from orkin

I was actually wondering if this was possible today, not even joking; you’re reading my mind! :D

Man, I've always wanted to try this, ever since I was a kid, and reading about how jangling keys have a lot of ultrasonics. IIRC it was in the context of ultrasonic remote controls or something like that. I was into electronics way early in life. So if you're doing any more of there I'd obviously like to hear if that's true and how it sounds, and I'd also like to hear how the voices and sounds we use with pet cats sound to the cat, compared to how normal voices sound to them. You could also try to record a medical ultrasound scanner, an ultrasonic cleaning bath, an ultrasonic humidifier, ultrasonic welder (used for plastic), ultrasonic motion sensor, ultrasonic rangefinder, the noise from switching power supplies, CRTs (I see that's already mentioned), the switching noise in inductors on a computer motherboard (if audible), the chatter of rodents, bird song, the breaking of glass (IIRC, glass breakage sensors listen for the ultrasound components of that noise), and more.

Every content is so unique and knowledgeable.

This is very interesting. I'd love to hear just ... normal stuff but the parts we can't hear. Like, what does a vacuum cleaner sound like, or a hairdryer, or a laptop? I don't have the money for a mic like that, but if I did, I'd go to town with it! Learn about everything.

I've been looking for a video like this for YEARS. My dog gets freaked out when it's windy outside, and I've always wondered if our house produces ultrasonic sounds that are the source of his anxiety. Thanks for spending the time and the money to do this! You should record some cheap switch mode power supplies. I find that the cheap ones can often produce coil whine in the human hearing range, especially when not under load. I've always suspected that the 5V-12V DC transformers that power many of our electronics are annoying the hell out of our pets, but I've never been able to confirm this. It would be interesting to see if there is significant ultrasonic pollution in modern households.

Woah thats so cool!!

The last one is even human repellent. So powerful.

According to the latest audio research, the average person tops out at 20 kHz frequency range, but there outliers of people who can hear up to 24 kHz. However, when it comes to ultrasonic sound that is inaudible, the average person can feel the sound up to 50 kHz. Experiments have shown that if they take regular sound and cut off the ultrasonics people can notice/feel a difference. Anecdotally, people have noticed that high frequency recordings (192 kHz) have better imaging and staging than standard 44.1/44 kHz recordings, so I guess that by including that extra information it does convey additional info. 192 kHz does mean that you should get at least 96 kHz of accurate sound due to Nyquist-Shannon theory, which would explain better nuance in the sound.

The "squashing" is pretty similar to how NASA give infra red and UV imaging for extraterrestrial objects. And is comparable to some extent to X-Ray. Interesting stuff tho. Forget NASA, Infra red cameras works somewhat the same.

Thank you for the free pest repellent

If you have access to an ultrasonic cleaner, or have enough to pick up a small one, I'm quite curious what the cleaner would sound like while running and cleaning different surfaces (ceramic, metal, plastic for example).

0:35 "But to be clear, this is not a review of any of these devices." 12:09 "I would not recommend this device." 🤔😕 Just pulling your chain, Joe. Interesting video - thanks!

Those harmonics look really cool

Also, even if not intending to tone anything down, it's probably good for Foley sound effects, makes perfect sense. I can imagine the sounds being more accurate and sharper in tone.

I would love to see how an Ultrasonic Distance sensor and Ultrasonic Humidifier would look/sound! Amazing video!

We used to have a cat that would quickly run off if I jangled my keys near her. I don't know if she was reacting to the noise I could hear or an ultrasonic component of the sound.

That first "monster voice" comparison audio alerted my husky! I told her she's ok XD

There are actually plenty of interesting ultrasonic sound sources out there - bats echolocating, mouse squeaks, rustling paper/leaves, running water, jingling coins, keys and chains, crinkling aluminium foil, power supplies, inductive chargers, laptops and other electronics, gas leaks and hissing sounds

Interesting to determine Ultra Sound in a car (moving parts can show distress by squeaking), insects perhaps speaking to each other, flat-screen TVs etc., and just placed outside your home - a railway train going past? Super video, by the way.

This is a very interesting and spectacular topic. Thanks for the great video and investigation.

this video deserves views

Interesting but probably not old idea for me, as have tinnitus AND some of those WERE SUPER ANNOYING , but ya did warn, thx for that; and why took out hearing devices👍🏻. Was interesting for dog whistles as they always claim to be “silent”, but as we saw and heard, they never are and ppl can hear them; on the other hand…..the anti barking things were silent, that would be cool for a “silent dog whistle”, lol. Thx Thio, your vids are always interesting and “thought provoking”; have good one ✌🏻

The frequency range overlaps with long wavelength radio. Examples are the radio signals linked to an atomic clock broadcast at 60khz (MSF Anthorn, UK) and 77.5khz (DCF77 near Frankfurt, Germany). Stretches understanding of these phenomena somewhat.

Thank you for great video! as a Paranormal team from Yorkshire UK we capture many EVP recordings ,and your video inspired me to upscale one of our recordings, which we could not hear what it said? Using software, i raised the level and heard voices that was not heard through normal hearing! Once again Thank you for the inspiration! we are on Facebook if you want to discuss Thanks again and well done!

11:23 i'm 18 and i'm able to hear the entire thing at normal frequency, so my ears are still good... (they're out of warranty so they better stay like that)

I once attended a demonstration in my city where an expert showed us bat sounds. He had a device that did what you do, record de echolocation sound and play it back in a lower frequency (and maybe slower). He could identify the kind of bat too.

I don’t remember how I became subscribed to your channel but the past me that I don’t remember rocks! :)

this is a very cool video. thank you for the ten things to speed up my computer. disabling windows animations made a big difference on how fast screens load. thank you.

get them while there hot!! good luck TJ!!

I just thought of something... maybe you could look into ENCODING INFORMATION into that SUPER ULTRASONIC range and using an ultrasonic speaker to send it across the room to you amazing microphone and see if the information is actually transmitted!!! OH THAT WOULD BE AWESOME!!!! :D

This might be helpful for detecting sounds that drive your pet crazy but you can't hear. A bit pricey though. As kids, my brother and I were annoyed by a high-pitched squeal from a department store escalator while our parents were like, "What are you talking about?"

Great video. Learn another thing! Ps i knew for example having speakers that go well beyond 20khz is that if such frequencies reach the tweeters and they could produce it they could ruin the total sound because of distortion. But the + on mics was new for me.

I would like to see other common sound sources also produce ultrasonic sounds. For example airplane jet engines, trains braking, table saw cutting metal, a water jet cutter in action, etc. And how do bats sound when they are toned down?

So cool. Thanks

ok but I need the stop dog barking things as my dog barks at - someone going upstairs -someone coming downstairs -someone thinking of doing either and heading towards stairs -the fireplace -the dishwasher -the oven -putting dishes away -taking out a dish from another dish -the vacuum -the toilet flushing -the water pumping in general -any reflection on the ground provided by sunlight -the broom -driving along in a car (though a face mask over the eyes somehow works) so a link would be nice, hes kinda special

Cool video, very interesting

I used to be able to hear up to 22kHz when I was younger. Now it's down to 18.5kHz. There used to be plenty of electronic devices that made annoyingly loud very high pitched noises that other people couldn't hear.

this is a video comment this video was pretty sick bro, i'm not too sure if those were all just recording harmonics bc idk how definitive or finely-stepping you were in your testing of that hypothesis is all

2:24 Oh Gosh... Hahahaha 5:54 Dog Whistle 2 (-80% Pitch) Imagine hearing this at 3am

I WAS wondering yes!