REQUEST: The CZcams algorithm is VERY STUPID and doesn't handle "non-typical" topics for a channel well, so if you enjoyed the video PLEASE LIKE 👍 so it will learn that it's actually a decent video!
How about stuff around the house that deals with pressure? i.e. water heaters, air compressors, pressure cooker...? Also this probably would be neat to hear "coil whine" from small power supplies, or old CRTs, those are barely on the top of the human hearing range
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.
@@thisisyourcaptainspeaking2259 hard to tell. They are only active during night mostly during the darker time of the year so it’s pretty much impossible to actually see them. But they tend to sit in one spot for quite a while and suddenly change position very fast and then maybe swirl around or sit in the new position for a while again. It is possible they scan for food when they do this. When I first heard this sound I thought it was something else but it was something I would hear many times over the years and found out it was actually bats doing that
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.
*at a sample rate of 192khz, any sound recorded that is higher pitched than 96khz will be reflected back down the audio spectrum as aliasing (incorrect frequencies being produced). Usually this is resolved by using a filter (digital or analogue) to prevent any sound over half of the sampling rate from being captured and recorded. (Nyquist theory)
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.
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.
@@vipervidsgamingplus5723 omg a ticking clock will make anyone snap! My old doctor had one in his exam room. He’d leave you waiting in there forever and all you’d hear was the clock. I wanted to smash it to pieces.
It’s probably just your family trapping you in their servers-get a new phone - and get out of the game whike ya got a lil sanity left cause integrity, honesty, and all that Bs ain’t coming back
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…
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 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 CZcamsrs 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. 😂
@@fred-youtube possible that any “undertones” could cause sympathetic vibration s on the ear but I agree with you. Sounds Ive 20khz shouldn’t be too damaging to human ears
Would you be opposed to describing why you feel that way? What device where you using? I was interested in getting the anti-bark dog device, but now you've raised a concern I hadn't considered.
@@fred-youtube I haven't done research (this is just a thought): Just like how you can't see ultra-violet light, but it can still give you sunburn, perhaps ultrasonic can do the same? I've never heard this claim before, but I also haven't looked into it.
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.
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.
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!
I had high sensitivity to high frequencies as a young person and tried my best to take care of my hearing, even wearing earplugs to some music concerts and when mowing my lawn, etc. This sensitivity stayed consistent even through my 30's and I expected to maintain some high-frequency hearing later in life. However, I lost most of the upper octave during my 40's and now hear only up to 13kHz or so, according to my own testing :(. I'm *very* disappointed, but I did experience a couple of loud music concerts without protection as a teenager, so everyone *please* take care of your hearing. We all lose some sensitivity with age, but you can definitely minimize hearing loss by protecting yourself from short-term noises above 100dB and long-term noises above 80dB. If you've ever experienced dullness or ringing in the ears after a loud concert, you've already done permanent damage to your hearing, so STOP and make sure that it never happens again. Also use hearing protection when shooting guns, etc. You may not prevent all age-related loss, but you certainly want to enjoy full-range hearing throughout your lifetime.
@@antibrevity Believe it or not, that's actually why I got my hearing tested...we suspected hearing loss. Everything is fine (more than fine) in the upper pitch ranges, but in the mid to low? I've got some loss. I was prescribed hearing aids. I'm only 22. Thankfully my hair hides my hearing aids naturally pretty well, because I get self-conscious sometimes.
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?
I did an experiment where for a few months I recorded bird chirps on high end mics and slowed them down and down pitched. what I discovered is for each quick chirp there are a LOT of different chirps.what I was hearing was a series of "messages" all packed into one half second chirp. it was like a .ZIP file. Then I started thinking that bird brains process information differently, maybe even their perceptions of time.
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.
That explains why, when walking around my neighborhood at night as a kid, I could "hear" if someone's TV was on if their door was open....not hear the voices on the TV but could sense if a TV was on....
When looking at a CRT vacuum tube TV with the cover off, I could hear a hiss but I think I was hearing the high voltage circuit (the toroid type) I think it was called a yoke. If you’re unlucky it would be covered in dust and arc over a few times.
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
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.
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!!!!
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
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!
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.
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?)
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.
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.
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.
@@gblargg The wave graphs are essentially just graphs of air pressure per time. And if you put two uniform and identical waves over each other, they add up. If they're offset by 180° they'll not increase the intensity but the frequency of the wave. And this slighter (because some of its energy has gone into the wall and other objects it was bouncing off of) wave that's double the frequency is perfectly explainable using my explanation. But if you have a better explanation, tell me.
@@Lampe2020 Two sine waves of the same frequency but different phases added gives a sine wave of the same frequency, but a new phase and amplitude. Same applies to a more complex wave of multiple sines (harmonics) at different frequencies. If you had a complex wave of many different harmonics and add at different phases, you might suppress the fundamental lowest frequency and reinforce higher harmonics, but you're never shifting frequency. The only way to add or shift frequencies is through a non-linear process, like clipping, multiplying two waves by each other (modulation), a non-linear mapping like exponentation, etc.
@@gblargg The pressures should add up if they're applied at the same time. Why shouldn't they add their frequencies? A little experiment: If I have to lines of water (it's a fluid, like air but less light and thin) and tap regularly in both of them synchronously the shock waves add their amplitude at the meeting point. If I make a 180° phase shift I tap left-right-left-right-... quickly. This makes double the frequency and exactly the same amplitude of waves at the meeting point. Because the second line of sound waves is an echo of the first one (as of my understanding), they've lost some energy, noticeable in an amplitude loss.
@@Lampe2020 Those lines of water would have higher harmonics that are reinforcing, with the fundamental being canceled out. You can demonstrate the fact about sine waves by using your favorite graphing program/site and looking at sin(x)+sin(x+3.14/2) (quarter phase shift)
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.
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.
Even though the "user" (scammer) that replied to my post has copied ThioJoe's avatar pic I have watched Thio's videos about such things so I suspected it wasn't real. Clicking on that fake avatar pic took me to an empty CZcams channel, confirming that it is really & truly a scam.
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.
Old TV's used ultrasonic for their remotes, and dangling keys (Because they have ultrasonic sound components) would trigger them, so yes there are ultrasonic sounds in dangling keys
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.
I too could hear CRT's. We had the PC's sitting in the back of the class room and I could tell the monitor was still on. The teacher couldn't hear it nor most of the class.
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.
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.
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
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).
Yes, even though I have substantial hearing loss and wear hearing aids, when using an ultrasonic cleaner I remove them and don a headset because the cleaner does make a very faint crackling sort of sound. I need to protect what's left of my hearing.
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.
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
Spoiler, THEY TOTALLY DON'T WORK, I've tried over 20 different anti-pest ultrasonic devices, NONE OF THEM WORK, not even against raccoons and squirrels which were my biggest nightmare in my attic. EVEN had one that looked like a loud speaker, assuming that was louder for them. STILL heard scritching and scratching above my head. They were still pooping under my car hood. They're terrible.
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.
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 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!
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!
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.
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.
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.
Great video but: aliasing comes from too low sampling rate. It means that there were sounds of higher frequency which the computer couldn't handle because of the Nyquist rule. On spectrogram it appears like lines "bounced" from the top frequency. To avoid aliasing we use high cut filters tuned to cut everything higher than whats Nyquist law ensures to be properly sampled.
That's how aliasing looks, like it bounces off the top (for a changing input frequency). It could occur if there's overload past the low-pass filter, e.g. with loud sounds. Or even before it, if they clip, creating loud harmonics above the Nyquist limit.
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.
Wow. Is it possible to record fireworks/explosions with this mic then by squashing down demonstrate what dogs/cats hear when they are terrified of those sounds? :)
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.
@@ThioJoe Ultrasonic sensors work by sending out a sound wave at a frequency above the range of human hearing. The transducer of the sensor acts as a microphone to receive and send the ultrasonic sound. Our ultrasonic sensors, like many others, use a single transducer to send a pulse and to receive the echo. So conclusion it will produce the sound
@@ThioJoe I have those sensors. If you put your ear real close to the transducer, you can actually hear a "tick" every second or so. Pitched down it's probably a short "bip" or so.
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?
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
Awesome video! What a cool idea. I'm curious, when you say you pitched it down 60%, what exactly does that mean? I think measuring in terms of octaves or semitones would make more sense. Next to record, you could try insects, the general "outside", brushing your teeth with an ultrasonic toothbrush, cymbals, or sibilant noises. It might also be cool to try and somehow record underwater sounds where higher freqencies may be more prevalent.
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 CZcams, 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
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.
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?"
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)
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
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
Actually this is pretty common. It's already used by Google to link a Chromecast in guest mode, the Chromecast will play ultrasonic sound to transmit its ID and your phone will hear it and be able to link.
@@ET2carbon I've only heard of FM in reference to a specific type of modulation used in radio technology. FM radio transmissions (from what I can remember) send varying frequencies within a range. The easiest way to explain it would probably be with an example so lets assume you're listening to 95.5 MHz on your FM radio, signals from 95.5 to 95.9 might represent the amplitude of the right audio channel and signals between 95.0 to 95.4 might represent the left audio channel. The farther the signal is from the center (95.5) the higher the amplitude on that channel. Speaker signals are just a series of pulses at different amplitudes so the conversion from frequency representation to the actual left and right audio signals are pretty straight forward (at least for traditional FM). The sample rate, the number of pulses per second, is determined by the signal frequency so in this case you get 95.0 to 95.9 pulses per second which is fast enough that it's effectively the same as having a true continuous signal of varying amplitude (this is also how Pulse Wave Modulation or PWM works though there are some limitations). To be clear I don't remember all of the exact details of how FM works (for example I may have the ranges wrong). From my understanding modern FM radios send an additional radio signal using a more modern modulation method for HD audio and meta data, that data actually comes in as a digital signal which requires additional processing to turn it into speaker/amp signals but it's more resilient to interference and can effectively send more data. Newer modulation methods almost always send some form of encoded binary (digital) signal and some actually combine amplitude modulation and frequency modulation techniques. You could apply the traditional Frequency Modulation technique to ultra sound but I'm not sure if it would still be considered FM and it's probably better to actually use a newer modulation technique to get the most out of the available bandwidth.
@@grn1 thank you for your reply to my comment. I'm a retired US NAVY Electronics Technician specializing in communications. You just described AM - Amplitude Modulation (in the first part of your comment) Going back to the first person who commented, technically the encoding they suggested to send ultrasonically would require a receiver tuned with a (mixer circuit) oscillating frequency matching that of the suggested "ultrasonic" signal. This gets to be ultrasonic where it would require a receiving capsule (diaphragm in ultrasonic range) to capture ultrasonic sound pressure and the pressure would only capture cycles of acoustic energy (not data utilized within encoding). So, we use carrier frequencies. That means modulating "intelligence" onto a carrier frequency so it can be sent long distances. The higher the frequency the further the signal can be transmitted. (HF UHF VHF SHF EHF) [my expertise was SHF and EHF which is satellite 🛰 signals] Now, the HD in HD RADIO isn't "High Definition" despite the popularity of the term. It literally just means the initials HD. The HD signal is encoded over FM but it's higher bandwidth with higher separation between channels. You mentioned sample rate, that's the rate in which the digital to analog to digital conversion takes snapshots of a waveform many times a second. It doesn't have anything to do with energy transmissions as it's an algorithmic term.
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.
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.
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.
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.
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
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!
Our mouths already produce ultrasounds, as you can hear details in the pitched-down voice you didn't hear in the original. Other ultrasound producing household items are metal objects, like a bunch of keys or a music box; and wet, watery sounds. Try squeezing a wet rag or a sponge near the mic and pitching that down. Boom, ultrasound.
I wish you had some of the many ultrasonic units used commercially/industrially for position sensing, level detection, etc. I've always wanted to know what they sounded like. Sadly, I'm retired so I couldn't even get you some of them anymore.
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.
There is a device that is supposed to stop teenagers from gathering near mall entrances and other areas. I could hear those well into my 30s, but I haven't noticed any for a while. I don't know if they got outlawed here, or if I'm just getting old. But I'd be interested to see how they'd show up.
When I was a kid, we had an old tube TV with 3 channels. With the volume all the way down, I could hear the difference between the channels and my brother and I would play a game where I tried to guess the channel based on the frequency. I was the only one that could hear it, and to this day, they think I was faking it. Its a very high frequency, almost like the unnoticeable ringing in your ears when it's completely silent. 20+ years later, I come to find out during a ultrasonic therapy session on a knee, that I can hear ultrasound through my body. Again, skepticism from medical staff untill...I was accurately calling out changes in frequency during an appendix ultrasound. I didn't even know the frequency changed during an ultrasounds until I got one. It was almost like I was hearing it in the middle of my head as apposed to my ears, like if I had a ear bud in my mouth. I would enjoy finding out if anyone else has this super power?
Well I had an ultrasound on my eyeball and I didn't hear a thing so I'm not who you are looking for... but cool story. There are a lot of odd things that we don't know are possible.
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 ✌🏻
Some things that are not meant to make noise, actually _do_ make noise, especially electronics. Some of them, like that last thing you tested, are hovering juuuust inside hearing range, that you can _just barely_ hear some sort of fuzz or buzzing if you stop and listen closely. It might be interesting to take a look at some of those, to see what we are _not_ hearing.
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.
I’m probably a bit late to the party, but I think just recording the sound of the animal (e.g. dogs bark) and then playing that back the way they would hear it would be awesome!
I've become fond of audio spectrum graphing tools on my android phone. These sample the phones mike up to 48khz and displays results as a horz waterfall (H=time, V=freq, color=intensity), which lets me see sounds up to about 24kHz. I park my car in a multi-level garage, and there are never any birds present. It seems bird repellers have been installed which generate chips, swoops, clicks and other sounds I can just hear with my hearing aides, but my phone picks up easily.
I know that in some poorly designed power supplies, there are the copper coils that make high pitch sound as the current passes by them. You can find them almost everywhere. In my case it's my monitor's power supply that annoys me during the night. There is a diode in the front of the monitor that blinks when in sleep mode and you can actually hear the power supply changing the pitch of the sound.
I had a drum teacher years ago who also rode mountain bikes. She kept this electronic dog repeller thingie. It looked like a garage door opener with a round button on it. Both me and my sister were there at the time, and I pushed the button, and it hurt both of our ears. I can't really describe the sound because there wasn't really any sound, but imaging a super loud concert without any noise. It just hurt anytime I pushed the button. My sister was reacting to it in the other room where she was with the teacher, and they both came out and the teacher was like uhhh you guys can hear that? Yeah we can. It was really weird. I can also hear bats too. Their sonar sounds like a cricket is behind my ear
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.
REQUEST: The CZcams algorithm is VERY STUPID and doesn't handle "non-typical" topics for a channel well, so if you enjoyed the video PLEASE LIKE 👍 so it will learn that it's actually a decent video!
CZcams algorithm is very weird.
@@_SJ Totally true.
I found that with my channel. By the way, how did you get Channel Guidelines?
I always LIKE your videos.
How about stuff around the house that deals with pressure? i.e. water heaters, air compressors, pressure cooker...?
Also this probably would be neat to hear "coil whine" from small power supplies, or old CRTs, those are barely on the top of the human hearing range
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.
i can hear bats, they have a very metalic sound
@@zaftra Some bats echolocate up to 200kHz, many around 30Khz and depending on conditions, much lower frequencies such as when they aren't feasting.
we have a type of bats here and I can hear them very clear when they echo locates, it is actually a pretty annoying sweeping sound they do
@@Pulverrostmannen Can you hear them while they're feeding or are they resting?
@@thisisyourcaptainspeaking2259 hard to tell. They are only active during night mostly during the darker time of the year so it’s pretty much impossible to actually see them. But they tend to sit in one spot for quite a while and suddenly change position very fast and then maybe swirl around or sit in the new position for a while again. It is possible they scan for food when they do this. When I first heard this sound I thought it was something else but it was something I would hear many times over the years and found out it was actually bats doing that
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.
glad to see another dan worall fan here
Fabfilter is quite useful
dan Worrall fans unite. what a legend
*at a sample rate of 192khz, any sound recorded that is higher pitched than 96khz will be reflected back down the audio spectrum as aliasing (incorrect frequencies being produced). Usually this is resolved by using a filter (digital or analogue) to prevent any sound over half of the sampling rate from being captured and recorded. (Nyquist theory)
@@ASMRCulture Oooops, you are correct it should have been half the sample rate or 96kHz. Apparently I was only half thinking when I wrote it. LOL 😂
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.
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.
Trying to solder while hearing the clock ticking made me snap at my mother. She took the batteries out of the clock pretty quickly.
Yeah I can hear it too. I’ve tried a few different ones over the years. Drives me nuts!
@@vipervidsgamingplus5723 omg a ticking clock will make anyone snap! My old doctor had one in his exam room. He’d leave you waiting in there forever and all you’d hear was the clock. I wanted to smash it to pieces.
It’s probably just your family trapping you in their servers-get a new phone - and get out of the game whike ya got a lil sanity left cause integrity, honesty, and all that Bs ain’t coming back
Places have started to put out high end sound generators in places to get rid of teenagers, since adults can't hear it.
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…
I could hear them too, those whistling sounds coming from people's yards.
I can hear the rat one and it goes eeeeeeeeeeeeeeeeeeeee
I don’t know why I can hear it but
Hi, are you a dog, or a cat?
Im surprised people cant hear them to be honest. Im 32 and can still hear them loud and clear.
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.
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 CZcamsrs 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. 😂
Why do you think it gave you tinnitus?, a human ear literally can't take (A properly made, above 20khz) one in
ant i love your videos man
@@fred-youtube possible that any “undertones” could cause sympathetic vibration s on the ear but I agree with you. Sounds Ive 20khz shouldn’t be too damaging to human ears
Would you be opposed to describing why you feel that way? What device where you using? I was interested in getting the anti-bark dog device, but now you've raised a concern I hadn't considered.
@@fred-youtube I haven't done research (this is just a thought): Just like how you can't see ultra-violet light, but it can still give you sunburn, perhaps ultrasonic can do the same? I've never heard this claim before, but I also haven't looked into it.
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.
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.
You know you're getting old when 10:44 is completely silent and then he goes on to say "As you can hear..."
oof, well you're not missing much, it's just annoying
It could be poor quality speakers and stuff too
Apparently 12Khz is hard to hear for people over 50. If you're younger than that, you might want to check your speakers.
All you're missing is pure earsplitting pain, don't worry.
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.
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!
I had high sensitivity to high frequencies as a young person and tried my best to take care of my hearing, even wearing earplugs to some music concerts and when mowing my lawn, etc. This sensitivity stayed consistent even through my 30's and I expected to maintain some high-frequency hearing later in life.
However, I lost most of the upper octave during my 40's and now hear only up to 13kHz or so, according to my own testing :(. I'm *very* disappointed, but I did experience a couple of loud music concerts without protection as a teenager, so everyone *please* take care of your hearing. We all lose some sensitivity with age, but you can definitely minimize hearing loss by protecting yourself from short-term noises above 100dB and long-term noises above 80dB.
If you've ever experienced dullness or ringing in the ears after a loud concert, you've already done permanent damage to your hearing, so STOP and make sure that it never happens again. Also use hearing protection when shooting guns, etc. You may not prevent all age-related loss, but you certainly want to enjoy full-range hearing throughout your lifetime.
@@antibrevity Believe it or not, that's actually why I got my hearing tested...we suspected hearing loss.
Everything is fine (more than fine) in the upper pitch ranges, but in the mid to low? I've got some loss. I was prescribed hearing aids. I'm only 22. Thankfully my hair hides my hearing aids naturally pretty well, because I get self-conscious sometimes.
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?
I did an experiment where for a few months I recorded bird chirps on high end mics and slowed them down and down pitched. what I discovered is for each quick chirp there are a LOT of different chirps.what I was hearing was a series of "messages" all packed into one half second chirp. it was like a .ZIP file. Then I started thinking that bird brains process information differently, maybe even their perceptions of time.
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.
Cry tvs was mad irritating as a kid. Parents never understand what I was talking about
I'm actually really curious about this, the deflection is a sawtooth wave so it should have a bunch of harmonics in there
That explains why, when walking around my neighborhood at night as a kid, I could "hear" if someone's TV was on if their door was open....not hear the voices on the TV but could sense if a TV was on....
Yes
When looking at a CRT vacuum tube TV with the cover off, I could hear a hiss but I think I was hearing the high voltage circuit (the toroid type) I think it was called a yoke. If you’re unlucky it would be covered in dust and arc over a few times.
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.
By using this microphone, I can have an idea what my cat is hearing 🐈
Lol
Lol
No shit
you sound like the sweetest little grandma sitting on the porch
no duh
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
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.
Was it a reasonably smooth frequency response? I thought those were made to resonate at 40 or 44khz
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.
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!!!!
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
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!
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.
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?)
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.
That would be a big bruh moment
Cats plotting with dolphins?
Calling out your naaame over and over.
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.
In a store near me (In the UK) there is always a (consistant) high pitch noise in there, could it be a poor quality rodent repeller?
@@fred-youtube some stores use them to try to repel "undesirable" groups of teens...
Yup I hear the high pitch whine from electronics and lights all the time.
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.
Sine waves don't add like that. You can't double the frequency with a delayed version.
@@gblargg
The wave graphs are essentially just graphs of air pressure per time. And if you put two uniform and identical waves over each other, they add up. If they're offset by 180° they'll not increase the intensity but the frequency of the wave. And this slighter (because some of its energy has gone into the wall and other objects it was bouncing off of) wave that's double the frequency is perfectly explainable using my explanation. But if you have a better explanation, tell me.
@@Lampe2020 Two sine waves of the same frequency but different phases added gives a sine wave of the same frequency, but a new phase and amplitude. Same applies to a more complex wave of multiple sines (harmonics) at different frequencies. If you had a complex wave of many different harmonics and add at different phases, you might suppress the fundamental lowest frequency and reinforce higher harmonics, but you're never shifting frequency. The only way to add or shift frequencies is through a non-linear process, like clipping, multiplying two waves by each other (modulation), a non-linear mapping like exponentation, etc.
@@gblargg
The pressures should add up if they're applied at the same time.
Why shouldn't they add their frequencies?
A little experiment:
If I have to lines of water (it's a fluid, like air but less light and thin) and tap regularly in both of them synchronously the shock waves add their amplitude at the meeting point. If I make a 180° phase shift I tap left-right-left-right-... quickly. This makes double the frequency and exactly the same amplitude of waves at the meeting point. Because the second line of sound waves is an echo of the first one (as of my understanding), they've lost some energy, noticeable in an amplitude loss.
@@Lampe2020 Those lines of water would have higher harmonics that are reinforcing, with the fundamental being canceled out. You can demonstrate the fact about sine waves by using your favorite graphing program/site and looking at sin(x)+sin(x+3.14/2) (quarter phase shift)
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.
Thanks for the warning.
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.
Even though the "user" (scammer) that replied to my post has copied ThioJoe's avatar pic I have watched Thio's videos about such things so I suspected it wasn't real. Clicking on that fake avatar pic took me to an empty CZcams channel, confirming that it is really & truly a scam.
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.
Old TV's used ultrasonic for their remotes, and dangling keys (Because they have ultrasonic sound components) would trigger them, so yes there are ultrasonic sounds in dangling keys
@@fred-youtube thanks for the explanation!
@@fred-youtube lol that reminds me of years ago turning on the old tv in the morning it always made a high pitch sound 🤣
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.
I too could hear CRT's. We had the PC's sitting in the back of the class room and I could tell the monitor was still on. The teacher couldn't hear it nor most of the class.
22kHz is waaaay too high even for a teenager
@@sukhoy if you say so.
@@roadmonitoroz same here. I could tell if someone left a TV on from the sound.
i expect this type of videos in future ❤❤❤❤
Very interesting! I've wondered what these sound like for decades. Thanks
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.
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.
Interesting
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
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).
Yes, even though I have substantial hearing loss and wear hearing aids, when using an ultrasonic cleaner I remove them and don a headset because the cleaner does make a very faint crackling sort of sound. I need to protect what's left of my hearing.
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.
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
Spoiler, THEY TOTALLY DON'T WORK, I've tried over 20 different anti-pest ultrasonic devices, NONE OF THEM WORK, not even against raccoons and squirrels which were my biggest nightmare in my attic. EVEN had one that looked like a loud speaker, assuming that was louder for them. STILL heard scritching and scratching above my head. They were still pooping under my car hood. They're terrible.
Good to know
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.
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.
Same!
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!
Except when your the 0.1% of adults who can hear it still in their 30s...
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!
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.
The last one is even human repellent. So powerful.
I was actually wondering if this was possible today, not even joking; you’re reading my mind! :D
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.
It could also just be classical conditioning where he's either afraid of thunderstorms or sudden changes in light
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.
Great video but: aliasing comes from too low sampling rate. It means that there were sounds of higher frequency which the computer couldn't handle because of the Nyquist rule. On spectrogram it appears like lines "bounced" from the top frequency. To avoid aliasing we use high cut filters tuned to cut everything higher than whats Nyquist law ensures to be properly sampled.
That's how aliasing looks, like it bounces off the top (for a changing input frequency). It could occur if there's overload past the low-pass filter, e.g. with loud sounds. Or even before it, if they clip, creating loud harmonics above the Nyquist limit.
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.
Wow. Is it possible to record fireworks/explosions with this mic then by squashing down demonstrate what dogs/cats hear when they are terrified of those sounds? :)
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.
Could you do a ultrasonic sensor? One that would come with a Arduino kit?
If it's a sensor it might not produce sound
@@ThioJoe Ultrasonic sensors work by sending out a sound wave at a frequency above the range of human hearing. The transducer of the sensor acts as a microphone to receive and send the ultrasonic sound. Our ultrasonic sensors, like many others, use a single transducer to send a pulse and to receive the echo. So conclusion it will produce the sound
An ultrasound device is used to measure distance based on sound pulse generation and time till echo. Polaroid cameras used this technique.
@@ThioJoe I have those sensors. If you put your ear real close to the transducer, you can actually hear a "tick" every second or so. Pitched down it's probably a short "bip" or so.
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?
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
Awesome video! What a cool idea.
I'm curious, when you say you pitched it down 60%, what exactly does that mean? I think measuring in terms of octaves or semitones would make more sense.
Next to record, you could try insects, the general "outside", brushing your teeth with an ultrasonic toothbrush, cymbals, or sibilant noises.
It might also be cool to try and somehow record underwater sounds where higher freqencies may be more prevalent.
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 CZcams, 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
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.
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?"
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)
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
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
Actually this is pretty common. It's already used by Google to link a Chromecast in guest mode, the Chromecast will play ultrasonic sound to transmit its ID and your phone will hear it and be able to link.
@@ethanblake4 Some phones (Samsung I think) also have a feature like this to transfer data from an old phone to a new one.
that's called frequency modulation. FM.
IT'S LIKE A HUNDRED FORTY YEARS OLD
@@ET2carbon I've only heard of FM in reference to a specific type of modulation used in radio technology. FM radio transmissions (from what I can remember) send varying frequencies within a range. The easiest way to explain it would probably be with an example so lets assume you're listening to 95.5 MHz on your FM radio, signals from 95.5 to 95.9 might represent the amplitude of the right audio channel and signals between 95.0 to 95.4 might represent the left audio channel. The farther the signal is from the center (95.5) the higher the amplitude on that channel. Speaker signals are just a series of pulses at different amplitudes so the conversion from frequency representation to the actual left and right audio signals are pretty straight forward (at least for traditional FM). The sample rate, the number of pulses per second, is determined by the signal frequency so in this case you get 95.0 to 95.9 pulses per second which is fast enough that it's effectively the same as having a true continuous signal of varying amplitude (this is also how Pulse Wave Modulation or PWM works though there are some limitations). To be clear I don't remember all of the exact details of how FM works (for example I may have the ranges wrong). From my understanding modern FM radios send an additional radio signal using a more modern modulation method for HD audio and meta data, that data actually comes in as a digital signal which requires additional processing to turn it into speaker/amp signals but it's more resilient to interference and can effectively send more data. Newer modulation methods almost always send some form of encoded binary (digital) signal and some actually combine amplitude modulation and frequency modulation techniques.
You could apply the traditional Frequency Modulation technique to ultra sound but I'm not sure if it would still be considered FM and it's probably better to actually use a newer modulation technique to get the most out of the available bandwidth.
@@grn1 thank you for your reply to my comment.
I'm a retired US NAVY Electronics Technician specializing in communications.
You just described AM - Amplitude Modulation (in the first part of your comment)
Going back to the first person who commented, technically the encoding they suggested to send ultrasonically would require a receiver tuned with a (mixer circuit) oscillating frequency matching that of the suggested "ultrasonic" signal. This gets to be ultrasonic where it would require a receiving capsule (diaphragm in ultrasonic range) to capture ultrasonic sound pressure and the pressure would only capture cycles of acoustic energy (not data utilized within encoding).
So, we use carrier frequencies. That means modulating "intelligence" onto a carrier frequency so it can be sent long distances. The higher the frequency the further the signal can be transmitted. (HF UHF VHF SHF EHF) [my expertise was SHF and EHF which is satellite 🛰 signals]
Now, the HD in HD RADIO isn't "High Definition" despite the popularity of the term. It literally just means the initials HD.
The HD signal is encoded over FM but it's higher bandwidth with higher separation between channels.
You mentioned sample rate, that's the rate in which the digital to analog to digital conversion takes snapshots of a waveform many times a second. It doesn't have anything to do with energy transmissions as it's an algorithmic term.
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.
Those harmonics look really cool
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.
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.
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.
That first "monster voice" comparison audio alerted my husky! I told her she's ok XD
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
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!
Our mouths already produce ultrasounds, as you can hear details in the pitched-down voice you didn't hear in the original. Other ultrasound producing household items are metal objects, like a bunch of keys or a music box; and wet, watery sounds. Try squeezing a wet rag or a sponge near the mic and pitching that down. Boom, ultrasound.
I wish you had some of the many ultrasonic units used commercially/industrially for position sensing, level detection, etc. I've always wanted to know what they sounded like. Sadly, I'm retired so I couldn't even get you some of them anymore.
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.
2:24 Oh Gosh... Hahahaha
5:54 Dog Whistle 2 (-80% Pitch) Imagine hearing this at 3am
There is a device that is supposed to stop teenagers from gathering near mall entrances and other areas. I could hear those well into my 30s, but I haven't noticed any for a while. I don't know if they got outlawed here, or if I'm just getting old. But I'd be interested to see how they'd show up.
When I was a kid, we had an old tube TV with 3 channels. With the volume all the way down, I could hear the difference between the channels and my brother and I would play a game where I tried to guess the channel based on the frequency. I was the only one that could hear it, and to this day, they think I was faking it. Its a very high frequency, almost like the unnoticeable ringing in your ears when it's completely silent. 20+ years later, I come to find out during a ultrasonic therapy session on a knee, that I can hear ultrasound through my body. Again, skepticism from medical staff untill...I was accurately calling out changes in frequency during an appendix ultrasound. I didn't even know the frequency changed during an ultrasounds until I got one. It was almost like I was hearing it in the middle of my head as apposed to my ears, like if I had a ear bud in my mouth. I would enjoy finding out if anyone else has this super power?
Well I had an ultrasound on my eyeball and I didn't hear a thing so I'm not who you are looking for... but cool story. There are a lot of odd things that we don't know are possible.
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 thumbs up for this video is from my dog, she loved it!
Some things that are not meant to make noise, actually _do_ make noise, especially electronics. Some of them, like that last thing you tested, are hovering juuuust inside hearing range, that you can _just barely_ hear some sort of fuzz or buzzing if you stop and listen closely. It might be interesting to take a look at some of those, to see what we are _not_ hearing.
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.
I’m probably a bit late to the party, but I think just recording the sound of the animal (e.g. dogs bark) and then playing that back the way they would hear it would be awesome!
Ultrasonic mics mounted on parabolic reflectors are used for hunting electrical noises, like arcs on power lines
I've become fond of audio spectrum graphing tools on my android phone. These sample the phones mike up to 48khz and displays results as a horz waterfall (H=time, V=freq, color=intensity), which lets me see sounds up to about 24kHz. I park my car in a multi-level garage, and there are never any birds present. It seems bird repellers have been installed which generate chips, swoops, clicks and other sounds I can just hear with my hearing aides, but my phone picks up easily.
Every content is so unique and knowledgeable.
funnily enough, I could hear the second insect rappeller's entire range before its frequency was reduced
I'm fascinated by what they hear
I know that in some poorly designed power supplies, there are the copper coils that make high pitch sound as the current passes by them. You can find them almost everywhere. In my case it's my monitor's power supply that annoys me during the night. There is a diode in the front of the monitor that blinks when in sleep mode and you can actually hear the power supply changing the pitch of the sound.
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!
I love the names they give these devices, 'NEATMASTER' 😂
Never wanted an ultrasonic microphone so badly
It would be interesting to check musical instruments and audio play backs to see if there are extra sounds in there animals would hear?
I had a drum teacher years ago who also rode mountain bikes. She kept this electronic dog repeller thingie. It looked like a garage door opener with a round button on it. Both me and my sister were there at the time, and I pushed the button, and it hurt both of our ears. I can't really describe the sound because there wasn't really any sound, but imaging a super loud concert without any noise. It just hurt anytime I pushed the button. My sister was reacting to it in the other room where she was with the teacher, and they both came out and the teacher was like uhhh you guys can hear that? Yeah we can. It was really weird. I can also hear bats too. Their sonar sounds like a cricket is behind my ear
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.
Can we call this science? 💭
8:03 those extra lines are actually mixing products from the modulation applied during the “pitch-down” process.