Folks within the canine neighborhood are frightened that sounds we will’t hear could be bothering our canines. However we will’t examine for ultrasound with shopper tools, 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 will’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 discovered learn how to interface it with my tools. In January 2024, I printed a submit with directions on learn how to examine your own home and atmosphere for ultrasound that your canines may be capable to hear. I discovered that many unusual noises had an ultrasound element—issues like clickers, keyboard strokes, motors, even barking canines. However I used to be in search of length or intermittent ultrasound that could 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 out. You’ll be able to see my record of things that didn’t emit detectable ultrasound under.
I just lately 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 frightened about: sound that canines can hear however we will’t. However the sound was very quiet; it could doubtless be inaudible except a canine was very shut.
This ultrasonic noise was emanating from unusual AC/DC adapters. I’ve no less than 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 had been the adapters for:
- A ground lamp with a 24 V DC energy provide. It put out a bunch 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 bunch of frequencies peaking round 23,000, 28,000, and 33,000 Hz. This adapter even put out a little bit 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.
Word 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 unsuitable 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’ll be able to see blue and inexperienced bands within the 20–70 kHz vary that correspond to the peaks I listed above throughout the durations the lamp is on. Additionally notice that there isn’t any 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 traces had been created by the clicking of the distant for turning the lamp on and off.) For extra info on studying this sort of diagram, see the web page of examples that accompanies this submit.
I discovered yet one more merchandise that had a continuing, quiet, high-frequency sound within the human listening to vary plus sounds within the ultrasound vary. These sounds had 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 operate as energy provides for gadgets that use direct present and decrease voltage than what our wall shops present. They’re the issues that usually annoy us by taking over a couple of area on an influence strip. They’re also known as wall warts due to their bulk. That makes them simple to find in your house. Two of my culprits had been wall warts, and one had a profile nearly as small as a traditional AC plug.
What Do They Sound Like and How Audible Are They to Canine?
Listed here are recordings of the sounds, digitally altered to make them audible to people. There may be some unavoidable distortion, however you may 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 hooked up 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 the place the gadget was on and the place it was off so I might edit. See this picture.
- I modified the pitch to deliver it right down to human listening to vary.
- Typically 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 elements 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 had 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 a little bit greater than half an inch lengthy. For comparability, a 60 Hz wave reminiscent of we might hear in a thunderstorm is 5.7 meters or nearly 19 toes lengthy. The tiny ultrasound waves don’t journey far over distances as a result of they’re mirrored and absorbed so simply. It’s wager that even canines don’t hear sounds reminiscent of those I introduced above except they’re near the supply. The sounds aren’t blasting by entire 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 with the ability to choose up the sound at about 1 meter. You’ll be able to see the attenuation of the sound as I moved the mic on this picture.
Objects I Examined with Null Outcomes
Varied scholarly and lay articles embody lists of family gadgets which 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. Word that a few of these gadgets have been reported to scare canines (Grigg et al., 2021). However noises do not need to have an ultrasound element to take action, and we don’t know if the ultrasound element contributed to the worry response.
- new and previous lights: fluorescent, incandescent, LED together with ring lights, evening lights (which embody adapters)
- screens: desktop laptop, tablets, laptops, flat-screen TV
- motion-sensitive wildlife digital camera (Meek et al., 2014)
- laptop computer fan
- laptop energy adapters (I used to be certain I’d discover a offender right here, however no. The Apple gadgets had been all silent.)
- energy strips
- USB wall plugs (these are additionally AC/DC adapters). The one noisy one was the Fi collar plug.
- sensible plugs (two manufacturers)
- fridge, microwave, oven
- smoke alarms on standby (not beeping)
- distant controls (aside from sometimes the clicking of a key)
- ultrasonic humidifier
- area heater
- varied followers
A Particular Word about Sensible Plugs
Due to a viral social media submit from November 2023, many individuals are involved about the potential of so-called “sensible plugs” placing out ultrasound. Whereas it’s doable, neither of the 2 I examined put out any. I intentionally selected low cost ones, as a result of they’re much less more likely to have robust high quality management. An engineer identified to me that normal QC contains ensuring electronics don’t put out noises reminiscent of 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 will’t hear it.
Word that sensible plugs aren’t AC adapters. You may plug an adapter into one, although. Many sensible plugs notice 2.4 GHz or 5 GHz on the again. Don’t fear; these numbers confer with appropriate Wi-Fi sorts and aren’t audible sound frequencies to people or canines.
Objects That Produce Sound That Consists of Ultrasound
These aren’t the stealth gadgets that individuals are frightened about, however I used to be fascinated to seek out so many noisy gadgets that included ultrasonic frequencies. I created a web page of ultrasound examples that features photographs of the output of a few of these loud gadgets.
- laptop keyboard strokes
- clicker
- ultrasonic squeaker toy
- common squeaker toy (you may see an picture of the ultrasound elements of noise from the previous 4 gadgets right here)
- barks and whines of a small canine (Sibiryakova et al., 2021)
- clicks of varied switches (like on remotes to followers or lamps)
- smoke alarms doing a check beep
- laptop mouse clicks
- fingers 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 gadgets, 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 had been near such an merchandise, they might doubtless hear a louder sound than we do. Most apps that measure quantity, reminiscent of SPL meters for smartphones, don’t embody the ultrasound vary.
Folks regularly ask me about utilizing ear-muff kind ear safety for canines who’re frightened 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 normally forestall the transmission of smaller sound waves very effectively. In case your canine has been conditioned to put on ear gear, it could be a kindness to have them put on it as a lot as doable for grooming. The hair dryer and rotary instruments I checked had 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 primarily based on biology, not physics. It’s anthropocentric. Ultrasound is simply sound with a better 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, regardless that there are some oddball on-line articles that declare that is so. Take into account that canines’ listening to advanced to operate 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 occurring 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 doable {that a} fixed noise within the ultrasound vary might trouble some canines. It’s additionally doubtless 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 the ductwork and maybe the sound of the furnace itself coming by the registers. However I don’t “hear” these lengthy length sounds except 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 might discover it once they come to city. And a few individuals 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 supplies proof that we might not be capable to predict their response.
Limitations of My Testing
Within the curiosity of transparency, I’ve created a separate web page that delineates points of my dwelling setup that have an effect on the precision and accuracy of my knowledge, on this and different posts that current outcomes. I do not need managed laboratory circumstances. However I embody within the record how the constraints had been mitigated and why I could be assured within the outcomes I’ve introduced right here.
Conclusion
Two main takeaways:
- The “stealth” sounds I discovered are doubtless inaudible except 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 could 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 creator doesn’t focus on the speedy attenuation over distance of ultrasound, nor do they offer us 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 info related to this submit:
Copyright 2025 Eileen Anderson
References
Grigg, E. Ok., 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 house owners’ 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). Digital camera 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.
