The claims made by the Pawnix company sound too good to be true. I believe that is the case. The company makes assertions about its sound-cancelling headset that are not possible with current consumer technology and for which they don’t provide evidence.
There are many products that market to the concerns we guardians have for dogs who are sensitive to thunder and fireworks. Like many of the others, Pawnix’ touted benefits are not well supported by evidence.
Sound phobia is a serious condition. If you have a dog who is sensitive to sound, please seek the help of a vet who specializes in behavior, a certified behavior consultant, and/or a veterinary behaviorist. These professionals often work together and can help your dog by changing his emotional response, implementing behavior change protocols, and prescribing medications.
When investigating a product that fits snugly on my dog’s head and contains electronics, I expect to find details on safety testing performed by the company, cautions and step-by-step instructions for conditioning the unit, and a clear assessment of the product’s strengths and limitations. After buying a Pawnix, I studied the instructions that came with it, studied their website, and watched their videos. I found none of the above. I came away with grave concerns.
Looking for Ways to Protect Dogs from Unwanted Sound
Many of you have read my post about how you can’t soundproof a dog crate, especially from low-frequency sounds. The same goes for other soundproofing attempts within the home.
Some have seen my presentations (my webinar Sound Decisions hosted by The Science Dog and my webinar “Beethoven for Your Dog…Really?” at the Lemonade Conference 2021) in which I talk about the weak evidence for calming effects of music for dogs, and the fact that music specially written for dogs has been unsuccessful in peer-reviewed studies.
So many disappointments! I hoped for the possibility of active noise cancellation for dogs. It would work best in an enclosure like this prototype crate by Ford, where speakers could be mounted at a distance from the target area (you’ll see why below). This setup would have a better chance of working for sudden noises like thunder than sound cancelling headphones, but when I saw the Pawnix headphones advertised, I still bought a pair. Then I reviewed the literature. It turns out I should have done that first.
Sound Cancelling Headphone Technology
My master’s thesis was on active sound cancellation in an enclosure. Active sound cancellation works by using one or more microphones to sample incoming sound, an electronic processor to compute a sound wave that is 180 degrees out of phase with it, and one or more speakers to play this computed “anti-sound,” all before the original sound wave reaches the subject’s ear or a target area in a room. (I can hear my professor wincing at the term anti-sound, but it gets the point across. It’s still normal sound, though.)
When I performed the literature review for my thesis, I included articles on sound cancelling headphones. The particular challenge created by active noise control (ANC ) headphones, as opposed to ANC in a room or enclosure, is that the length of the path between the microphone and the speaker is very short. ANC implements a race between the speed of sound and the speed of electronics. Speaking from experience, it’s easy to lose that race, even in a large enclosure. So being able to compute and output the new sound wave during the time sound travels about an inch from the outside to the inside of the headphone is a challenge. However, when the sound is regular and predictable, ANC headphones can be effective. That’s why the ones for humans are marketed for riding on planes and subways.
Current Headphone ANC Doesn’t Cancel Sudden Sounds
I knew the limitations of active sound cancellation in headphones in 2008, so I focused my recent studies on whether they have been surmounted. They have not. Experts agree that ANC still works best for low-frequency, periodic sounds, such as engines and fans (Kuo & Morgan, 1999; Zhang & Wang, 2021). Consumer products are not yet available for sudden sounds (impulse sounds) or sounds above 1000 Hz because of the technical complexities, although there is progress in that area (Zhang & Wang, 2021).
The limitations of active noise control in headphones mean that the sounds that bother dogs most, the things we are trying to protect them from, are the very ones that sound cancelling headphones can’t really help with.
Active noise control is comparatively ineffective on:
- thunder claps (it may have some effect on the following long-term rumbles)
- short digital pops and clicks
- all digital beeps over about 1,000 Hz
The last two items can be addressed with passive sound control: the insulation in headphones. But as for the rest—insulation doesn’t provide much protection from low frequencies, and today’s sound cancelling headphones can’t significantly shield dogs from sudden sounds. A company that markets its noise cancelling headphones for thunder and fireworks is putting out incorrect information.
Pawnix’ Claims and Characteristics of the Headphones
- Pawnix has a conservative limit for the volume of the sound output to protect dogs’ ears.
- Pawnix recommends that the headset be worn in non-scary situations first, so as not to make it a predictor of scary things. (They do not thoroughly instruct how to create a good association through counterconditioning, though, nor do they link to the online resources that are available on the topic.)
- The stated active frequency range covers dogs’ hearing range well: 10–40,000 Hz (although it’s unnecessary since consumer ANC is ineffective for more than 95% of that range).
- Pawnix incorporates the option for playing music, which could provide a masking effect.
- Pawnix headphones provide some passive sound control via insulation.
- Pawnix headphones have not been experimentally tested for efficacy or safety on dogs in a controlled setting. The only “evidence” of their performance Pawnix presents consists of perceived changes in behavior of one dog who belongs to the founder of the company. Here is what they say:
“How Do We Know That It Works? First, we used audio testing technology to prove that the electronics were in fact cancelling the frequencies that were found to be problematic. Then, only after we felt it was mathematically sound, we put it on Emma in different loud situations and it worked. We could visibly see a difference in Emma’s behavior.”
I think the Pawnix company means well. But the above statement demonstrates a certain naiveté about science and evidence. The founder’s dog? That’s it?
Without unbiased testing, there is no evidence that the headphones work as claimed, and there is no assurance that they are safe (see below about the missing safety warnings). I emailed Pawnix to ask whether they plan on funding a study, but they did not reply.
- Pawnix explicitly claims that the headphones protect dogs from the sounds of fireworks and thunder. This is not possible to a significant degree. Check out these New York Times Wirecutter articles that include info on the limitations of sound cancelling headphones.
- What Your Noise-Cancelling Headphones Can and Can’t Do
- How to Block Fireworks Noise for Adults, Kids, and Pets
Two scholarly review articles on sound cancelling headphones for humans found that sudden noises were actually amplified, not cancelled, in some of the headphones tested (Ang et al., 2017; Rudzyn & Fisher, 2012). How can we know what our dogs are hearing?
- Several standard safety warnings and instructions included about headphones for humans are missing. You can read the safety instructions for Bose headphones to get an idea.
- Pawnix does not caution to remove the headphones if they get warm or if there is loss of audio. How can we check them frequently enough for overheating? And how would we know if there is loss of audio? If one of the most respected makers of sound equipment for humans gives these warnings about their headphones, should we not worry about a company only a few years old that shows us no evidence of quality control or serious testing?
- Feedback (often a crackling noise) can be a problem with sound cancelling headphones. How can we know if the Pawnix unit is generating it? Feedback could be a nightmare for a sound sensitive dog. The headphones might sensitize rather than protect. Here is an article about crackling feedback sounds from Bose.
- So-called “eardrum suck” may be present on the Pawnix. This is an unpleasant sensation some people experience when wearing some models of sound cancelling headphones. It is thought to be due to the filters used to control feedback (see previous bullet). We don’t know whether dogs are vulnerable to this disorienting phenomenon. We need to know this, and we need to know if there is help for our dogs if this were to happen on the Pawnix.
- The welcome video for the Pawnix includes the following statement: “The noise cancelling portion is a wavelength and always tuned up to 100%, because since this is a wavelength it does not hurt our dogs’ hearing.” This doesn’t make sense and raises doubts about the company’s knowledge of its own product. A wavelength is literally a distance. For example, the wavelength of a 200 Hz sound is about 5.6 feet. A sound’s wavelength doesn’t describe its intensity or volume. Every single sound has a wavelength (almost always a group of them) and this does not prevent loud sounds from damaging our ears.
- Two design annoyances:
- The built-in fabric hood prevents humans from testing the headphone output on our own ears and certainly appears that it would be hot for the dog.
- The control button and status lights are underneath the fabric, which makes them hard to use and is also worrisome from a safety standpoint.
“30 dB Noise Reduction”
The Pawnix, along with many other ANC headphones, claims a reduction of sound of up to 30 dB. This bears discussion.
First, when a company claims a 30 dB reduction in sound without specifying a frequency range, this doesn’t guarantee that any particular sound or frequency band will be reduced by that much. It’s an average. So, for instance, a low frequency rumble that we were concerned about might get only 10 dB of reduction, even if the sound overall is reduced by 30 dB. Some frequencies might actually increase in volume (see the scholarly articles linked below).
Second, the cap on the volume output of the headphones is a double-edged sword. It’s absolutely necessary; it would be dangerous to allow the unit to put out sound at a high volume. Dogs can’t turn down the volume or let us know why if they become uncomfortable. But a higher volume might be necessary to effectively cancel a particular sound. You can’t cancel a shout with a whisper.
Your Dog Can Still Hear You—But Why?
Pawnix states that your dog will still be able to hear you speak because they designed the headphones to cancel sound in frequencies that “affect dogs the most.” You can find this claim here, on the fourth page. A common way to exclude certain frequencies from an algorithm would be with a “band-stop filter,” which prevents a range of frequencies from being affected. The reason that this is a troubling claim is that the frequency range of human speech, 80–8,000 Hz, completely encloses the range where ANC works best. If they excluded that range, the headphones would hardly cancel sound at all.
The good news is that your dog could hear you just fine, but it’s probably because of inherent limitations to ANC and not a special adjustment Pawnix made. Speech is unpredictable and irregular. That’s why your dog can hear you (and any other irregular noises like speech), not because of a special algorithm that allows for human speech.
This may seem like a minor point, but it indicates a company that may not understand the technology behind its product and one that is not accustomed to how scientific evidence works.
The Paradox of “Relaxation”
Pawnix has in common with compression garments for dogs such as the Thundershirt that if poorly conditioned, it could shut down a dog. Some dogs appear to go into tonic immobility when swaddled. This can appear to some people that the dog is “calm.” This stillness and the caregiver placebo effect can both cause guardians to believe that a product is helping when it may be neutral or even harmful.
Somehow, we have gotten it into our heads that dogs who are freed of their fear and anxiety should just lie down and relax. Perhaps this is because of the sedative effects of some anxiety-reducing medications. Perhaps it’s because of the longstanding belief that quiet dogs are being “good.” But the opposite of a scared dog isn’t necessarily a snoozing dog. It’s a dog going about its daily business. It’s a dog exploring, eating, playing, and interacting with its human and animal family. And yes, sometimes napping. But not as a default.
I haven’t seen a dog acting normally in this way in any Pawnix videos. In the videos Pawnix provides, the dogs are motionless or moving stiffly while wearing the headphones. They seem unnaturally still; they crouch or sit with their heads motionless and often only their eyes moving. I haven’t seen a dog in a video wearing Pawnix with loose body language, soft eyes, a relaxed lower jaw, or anything to indicate they are happy and comfortable.
By stating that their headphones can protect a dog from the sounds of fireworks and thunder, Pawnix is claiming that their product can do something that the highest end human headphones currently can’t. Extraordinary claims require extraordinary evidence. Any evidence would be a great start. Pawnix states they used audio testing technology to prove that the electronics were in fact cancelling the frequencies that were problematic. So how about they publish the data? Show us the performance of the headphones, not only with constant sounds, but with sudden thunderclaps and the pops and booms of fireworks. And if the headphones were tested when not on a dog, which they imply, they need to be tested on dogs for behavioral responses as well.
I hesitated to publish this review for a long time. I wanted to test the output of the Pawnix, but the headset design and my lack of the equipment to give a fair test prevented me from doing so. Finally, I realized it was not up to me to disprove that they work. Pawnix is the one making the extraordinary claims. They are marketing a product that fits snugly on dogs’ heads and plays sound directly into their ear canals. It’s up to them to give us solid evidence of safety and efficacy.
What’s the Alternative?
There is not a consumer product on the market that can protect your dog from the sudden, low-frequency sounds of thunder and fireworks or make him feel significantly better about them.
If you want to try pure passive sound control, Mutt Muffs are effective at protecting dogs’ ears from engine noises and the company is straightforward about the capabilities and limitations of their product. They do not claim that Mutt Muffs help with thunder or fireworks.
For a dog with sound phobia or sound sensitivity, please see a certified dog behavior consultant, a veterinarian who specializes in behavior issues, or a veterinary behaviorist. And in the meantime, use careful sound masking to the best of your ability.
Copyright 2022 Eileen Anderson
- What Your Noise-Cancelling Headphones Can and Can’t Do
- The Pros and Cons of Noise-Cancelling Headphones
- How to Block Fireworks Noise for Adults, Kids, and Pets
- Why Noise Cancelling Headphones Are Not Enough
- Why Don’t My Noise-Cancelling Headphones Block All Sounds?
- Can Active Noise Cancelling Remove All Noise?
- Bose: Crackling Sound Heard in Noisy Environments (in noise-cancelling headphones)
Scholarly Articles Cited
- Ang, L. Y. L., Koh, Y. K., & Lee, H. P. (2017). The performance of active noise-canceling headphones in different noise environments. Applied Acoustics, 122, 16-22.
- Kuo, S. M., & Morgan, D. R. (1999). Active noise control: a tutorial review. Proceedings of the IEEE, 87(6), 943-973.
- Rudzyn, B., & Fisher, M. (2012). Performance of personal active noise reduction devices. Applied Acoustics, 73(11), 1159-1167. (Here’s a copy of the full article)
- Zhang, H., & Wang, D. (2021). Deep ANC: A deep learning approach to active noise control. Neural Networks, 141, 1-10.