Folks within the canine neighborhood are apprehensive that sounds we are able to’t hear may be bothering our canines. However we are able to’t verify for ultrasound with shopper gear, even smartphones, as a result of shopper microphones don’t detect sound above 20,000 cycles per second (20,000 Hz). They don’t have any motive to, since we are able to’t hear in that vary. However canines can. They hear as much as 45,000 Hz or increased.
My Seek for Ultrasound
In 2023, I purchased an ultrasound microphone and realized find out how to interface it with my gear. In January 2024, I printed a submit with directions on find out how to verify your private home and atmosphere for ultrasound that your canines may have the ability to hear. I discovered that many odd noises had an ultrasound element—issues like clickers, keyboard strokes, motors, even barking canines. However I used to be in search of period or intermittent ultrasound that may be generated by digital gadgets and didn’t have a element audible to people.
I didn’t discover any for some time, however I stored looking. You possibly can see my listing of things that didn’t emit detectable ultrasound beneath.
I not too long ago checked the sound atmosphere once more, and located some fixed, low-level, electronics-generated ultrasound in canines’ listening to vary that was not accompanied with something within the human listening to vary.
I discovered what folks have been apprehensive about: sound that canines can hear however we are able to’t. However the sound was very quiet; it might probably be inaudible until a canine was very shut.
This ultrasonic noise was emanating from odd AC/DC adapters. I’ve at the very least 20 of those in my home. I discovered three that put out a high-frequency noise that was outdoors of people’ listening to vary. These have been the adapters for:
A flooring lamp with a 24 V DC energy provide. It put out a gaggle of frequencies peaking round 21,000, 31,000, and 43,000 Hz.
An ornamental “Moon” lamp with a 12 V DC energy provide. It put out a gaggle of frequencies peaking round 23,000, 28,000, and 33,000 Hz. This adapter even put out somewhat sound when the lamp was off, however extra when it was on.
A Fi GPS collar charger that output 5 V DC. The USB adapter put out a band of frequencies peaking round 22,000, 30,000, and 45,000 Hz.
Notice that it was the adapters, not the lights or the charger placing out the sound. I spent lots of time pointing my microphone on the improper ends of issues!
The next picture reveals the ultrasound put out by the adapter of the ground lamp. The x axis is time and the y axis is frequency. You possibly can see blue and inexperienced bands within the 20–70 kHz vary that correspond to the peaks I listed above in the course of the durations the lamp is on. Additionally word that there isn’t a change within the sound output decrease than 20 kHz when the lamp is on. That signifies that we people can’t hear the adapter. (The skinny vertical strains have been created by the press of the distant for turning the lamp on and off.) For extra data on studying this sort of diagram, see the web page of examples that accompanies this submit.
I discovered yet another merchandise that had a relentless, quiet, high-frequency sound within the human listening to vary plus sounds within the ultrasound vary. These sounds have been coming from a battery charger for a Dremel instrument (8220). It put out an audible tone at 6,000 Hz, and harmonics (mathematically associated increased tones) at 12,000, 18,000, and 24,000 Hz. The charger itself (the half the place you insert the battery, on this case not the wall plug) has a built-in AC/DC adapter.
AC/DC Adapters
AC/DC adapters perform as energy provides for gadgets that use direct present and decrease voltage than what our wall shops present. They’re the issues that always annoy us by taking on multiple house on an influence strip. They’re sometimes called wall warts due to their bulk. That makes them simple to find in your house. Two of my culprits have been wall warts, and one had a profile virtually as small as a standard AC plug.
What Do They Sound Like and How Audible Are They to Canine?
Listed below are recordings of the sounds, digitally altered to make them audible to people. There may be some unavoidable distortion, however you will get the overall concept. To create these sounds, I did the next:
I recorded the sound in WAV format utilizing my Dodotronic 192 kHz ultrasound mic connected to my iPhone 12 Mini utilizing the free Ultrasonic Analyzer app.
I imported the audio file into the free sound software program Audacity on my Mac.
I utilized a high-pass filter to isolate the ultrasound.
I amplified the sign. The sound was so quiet that I wanted to amplify it to have the ability to see on the display screen the place the gadget was on and the place it was off so I may edit. See this picture.
I modified the pitch to carry it all the way down to human listening to vary.
Generally I amplified once more.
I exported the file as an MP3. The constraints of MP3s don’t have an effect on the sound high quality wanted for these recordings.
Flooring Lamp
“Moon” Lamp
Fi Collar Charger Plug
All the unique sounds have ultrasound parts in canines’ listening to vary, between 20,000 and 45,000 Hz. However the tailored variations are amplified within the above recordings; in all instances, the unique sounds have been a lot, a lot quieter.
For these of us who’re involved about them presumably bothering canines, there’s a blessing. Ultrasound waves are tiny. For example, the wave that corresponds to the frequency of 25,000 Hz is 14 millimeters, or somewhat greater than half an inch lengthy. For comparability, a 60 Hz wave akin to we may hear in a thunderstorm is 5.7 meters or virtually 19 ft lengthy. The tiny ultrasound waves don’t journey far over distances as a result of they’re mirrored and absorbed so simply. It’s a great wager that even canines don’t hear sounds akin to those I offered above until they’re near the supply. The sounds usually are not blasting by means of complete rooms.
The 2 lamps are inside about 2 meters of the place Lewis sleeps on my mattress. Whereas recording, I moved the ultrasound mic from the lamp’s energy adapter towards the place Lewis sleeps. The mic stopped having the ability to decide up the sound at about 1 meter. You possibly can see the attenuation of the sound as I moved the mic on this picture.
Objects I Examined with Null Outcomes
Numerous scholarly and lay articles embrace lists of family gadgets that will put out ultrasound. I selected the next gadgets from these sources, examined, and detected no ultrasound. Different manufacturers or fashions of this stuff may yield totally different outcomes. Notice that a few of these objects have been reported to scare canines (Grigg et al., 2021). However noises don’t have to have an ultrasound element to take action, and we don’t know if the ultrasound element contributed to the concern response.
new and previous lights: fluorescent, incandescent, LED together with ring lights, evening lights (which embrace adapters)
screens: desktop laptop, tablets, laptops, flat-screen TV
motion-sensitive wildlife digicam (Meek et al., 2014)
laptop computer fan
laptop energy adapters (I used to be certain I’d discover a perpetrator right here, however no. The Apple gadgets have been all silent.)
energy strips
USB wall plugs (these are additionally AC/DC adapters). The one noisy one was the Fi collar plug.
good plugs (two manufacturers)
fridge, microwave, oven
smoke alarms on standby (not beeping)
distant controls (aside from sometimes the press of a key)
ultrasonic humidifier
house heater
varied followers
A Particular Notice about Good Plugs
Due to a viral social media submit from November 2023, many individuals are involved about the potential for so-called “good plugs” placing out ultrasound. Whereas it’s potential, neither of the 2 I examined put out any. I intentionally selected low cost ones, as a result of they’re much less prone to have robust high quality management. An engineer identified to me that commonplace QC contains ensuring electronics don’t put out noises akin to coil whine or capacitor squeal within the human listening to vary. However there may be far much less concern concerning the ultrasound vary, for a similar common motive. We are able to’t hear it.
Notice that good plugs usually are not AC adapters. You may plug an adapter into one, although. Many good plugs word 2.4 GHz or 5 GHz on the again. Don’t fear; these numbers discuss with suitable Wi-Fi sorts and usually are not audible sound frequencies to people or canines.
Objects That Produce Sound That Consists of Ultrasound
These usually are not the stealth objects that persons are apprehensive about, however I used to be fascinated to seek out so many noisy objects that included ultrasonic frequencies. I created a web page of ultrasound examples that features photographs of the output of a few of these loud objects.
laptop keyboard strokes
clicker
ultrasonic squeaker toy
common squeaker toy (you may see a picture of the ultrasound parts of noise from the previous 4 objects right here)
barks and whines of a small canine (Sibiryakova et al., 2021)
clicks of assorted switches (like on remotes to followers or lamps)
smoke alarms doing a check beep
laptop mouse clicks
arms clapping
jingling keys
hand-held hair dryer
jingling canine tags
upright vacuum
small rotary instruments (e.g. Dremel)
Makita screwdriver and drill
Makita rotary hammer drill
For a few of these objects, the ultrasound element was among the many loudest of the frequency bands. As a result of canines’ listening to is extra delicate within the higher frequencies than ours, if a canine have been near such an merchandise, they’d probably hear a louder sound than we do. Most apps that measure quantity, akin to SPL meters for smartphones, don’t embrace the ultrasound vary.
Folks incessantly ask me about utilizing ear-muff sort ear safety for canines who’re terrified of thunder or fireworks. I all the time clarify that such gear can’t defend in opposition to the large sound waves generated by these low-frequency sounds. However these ear protectors can often stop the transmission of smaller sound waves very properly. In case your canine has been conditioned to put on ear gear, it might be a kindness to have them put on it as a lot as potential for grooming. The hair dryer and rotary instruments I checked have been loud within the ultrasound vary, on high of being loud in excessive frequencies people and canines can each hear. Clippers may additionally put out ultrasound, however I didn’t have any to check.
“Ultrasound” Is an Arbitrary Definition
It’s essential to know that sound doesn’t magically change when the frequency goes over 20,000 Hz. That boundary of 20,000 Hz for ultrasound is derived from “sound that’s too excessive for people to listen to.” It’s a helpful distinction, but it surely’s based mostly on biology, not physics. It’s anthropocentric. Ultrasound is simply sound with the next frequency. I all the time make the purpose in my sound webinars that we shouldn’t assume {that a} sound is aversive to canines whether it is within the ultrasound vary, despite the fact that there are some oddball on-line articles that declare that is so. Take into account that canines’ listening to developed to perform in that vary. Many small animals which can be prey to canids vocalize in that vary. It’s no coincidence that home cats can hear in that vary and even increased, too.
Something taking place above 20,000 Hz is a thriller to us. However it’s to not canines; it’s simply a part of their world. It’s fairly potential {that a} fixed noise within the ultrasound vary may hassle some canines. It’s additionally probably that many canines habituate to it, simply as many canines (and lots of people) cease noticing different ongoing stimuli. For example, the furnace is on in my home as I write this. There may be the sound of the fan blowing air by means of the ductwork and maybe the sound of the furnace itself coming by means of the registers. However I don’t “hear” these lengthy period sounds until I flip my consideration to them. Likewise, most of us who dwell in cities don’t discover the widespread 60-Hz hum of transformers. However individuals who dwell in rural areas could discover it once they come to city. And a few persons are instantly bothered by some ongoing sounds or by no means habituate.
I’ve an instance in one other submit of canines hanging round throughout a really obnoxious ongoing sound, even intentionally basking within the solar near the sound supply. This instance “proves” nothing about how all canines reply to sounds. Nonetheless, it gives proof that we could not have the ability to predict their response.
Limitations of My Testing
Within the curiosity of transparency, I’ve created a separate web page that delineates facets of my dwelling setup that have an effect on the precision and accuracy of my information, on this and different posts that current outcomes. I don’t have managed laboratory circumstances. However I embrace within the listing how the constraints have been mitigated and why I could be assured within the outcomes I’ve offered right here.
Conclusion
Two main takeaways:
The “stealth” sounds I discovered are probably inaudible until a canine approaches shut. Right here is a photograph of sound-reactive Lewis standing proper subsequent to the adapter for the ground lamp whereas he determines whether or not I’ve “webinar or Zoom treats” in a drawer.
The ultrasound generated by motors could be loud. Correctly conditioned listening to safety can be useful for canines present process grooming procedures the place a hair dryer or rotary instrument is used.
Others have discovered extra stealth ultrasound than I’ve, as described on this dramatically-titled CNET article. Nonetheless, the writer doesn’t talk about the speedy attenuation over distance of ultrasound, nor do they provide us a great sense of how loud the sounds are.
I’ll maintain performing periodic sweeps for ultrasound culprits in my space and report any findings.
Supplemental Supplies
There are two pages with data related to this submit:
Copyright 2025 Eileen Anderson
References
Grigg, E. Okay., Chou, J., Parker, E., Gatesy-Davis, A., Clarkson, S. T., & Hart, L. A. (2021). Stress-related behaviors in companion canines uncovered to widespread family noises, and homeowners’ interpretations of their canines’ behaviors. Frontiers in veterinary science, 8, 760845.
Meek, P. D., Ballard, G. A., Fleming, P. J., Schaefer, M., Williams, W., & Falzon, G. (2014). Digicam traps could be heard and seen by animals. PloS one, 9(10), e110832.
Sibiryakova, O. V., Volodin, I. A., & Volodina, E. V. (2021). Polyphony of home canine whines and vocal cues to physique measurement. Present Zoology, 67(2), 165-176.
