It’s long overdue to write about this. I have successfully desensitized and counterconditioned my clinically sound phobic dog, Zani, to electronic beeps using a novel but evidence-based method. Here are some concepts and practices that may be helpful to others working with such dogs.
This is part 1 of a two-part series. Please read part 1 before reading part 2.
It’s not always about quantity
If there’s one thing I’d tell anyone looking to desensitize their dog to sounds other than low-pitched bangs and explosions, it’s this: Think beyond volume control.
We believe that reducing the volume is an effective way to reduce the intensity of a sound and dull the sensation, which makes sense when it comes to the volume (and usually suddenness) of a sound that startles you.
For example, in the case of thunder and fireworks, volume is likely relevant: these are sounds that are loud and sudden enough to trigger an auditory startle response in mammals. And startle responses can trigger fear conditioning (Götz & Janik, 2011). It is a reasonable starting point to assume that volume and suddenness are essential to the response of thunder-phobic dogs.
Now, what about the sound of a dead battery in a smoke detector or the digital beep of a weighing scale that scares dogs? Do you really think that quieting these sounds would make them less scary for a dog with a cynophobia? To begin with, these sounds aren’t loud.
What makes a sound intense?
To tone down the intensity of sounds, we need to consider what is “intense” to a dog. We don’t know for sure, but with the help of science, we can make some guesses.
Let’s take a look at the characteristics of a quiet digital beep and why it scares dogs. First, let’s look at the waveform.
This is the beep of the scale.
This waveform image shows a beep lasting approximately 0.15 seconds. X The axis is time, Yeah The axis is amplitude. There are a few impressive things about this sound.
It’s abrupt. There’s no gradual transition between off and on. It starts instantly and is even until it fades briefly at the end.
For comparison, below is a waveform image of a bird song at roughly the same frequency.
Birdsong is impressive in its complexity despite its long duration: it is an abrupt noise, but it has a gradual attack (the audio term for the onset of a sound) unlike the abrupt onset of a digital beep.
Returning to the beep, there are a few other things we can learn about it through analysis. First, we know its frequency, which is about 3,900 Hz, but that’s not visible in the diagram. Also, because the sound is generated by standard consumer circuits and played through consumer speakers, it doesn’t contain any sounds above 20,000 Hz, which means that to animals like dogs who can hear up to 40,000 Hz, the sound may sound strange and choppy.
So what does this mean? We don’t know why some dogs are afraid of sounds in certain frequency ranges. However, we can make some guesses as to why some of the other features of this sound are perceived as “scary.” Studies have shown that dogs are not as good at detecting sounds as humans (Fay and Wilber, 1989, p. 519). Add to that the short duration of the sound, which makes it harder for anyone to find. Furthermore, these beeps are often pure tones, which can also be difficult. According to Barber et al., “broadband sounds are generally easier to detect than pure tones.” This means that pure tones and sounds that omit high frequencies can be difficult to find. Finally, “…therefore, [for a dog] “We estimate the distance to a sound source only if it is at the expected volume” (Barber et al., 2020). In other words, we can pinpoint the location of a sound source more accurately than if the sound is too quiet.
To be clear, the above conclusions are speculations: they are based on known information, but there is no experimental evidence to back up the speculations.
Have you ever tried to find the one that’s making the sound of a dead battery when you have multiple smoke detectors? It’s a maddeningly difficult task. Now imagine what it would be like if you were as poor at localizing sounds as a dog is. The sound would be strange and would lack many of the frequencies found in analog and natural sounds. Needless to say, every time that sound is made, it’s over before you even realize it had actually started.
These sounds can be hard for dogs to detect, and turning them down may make the situation worse rather than better. I’ve observed this with my own dogs.
How can I reduce the intensity of the beep?
The volume issue sounds like bad news at first. Adjusting the volume is the easiest way to change the sound—just turn a knob or drag a slider. But the good news is that there are lots of ways to change your digital sound and find ways to make it less scary.
Here are some examples:
All of the short audio files below first play a “pure” sine wave beep, then a modified beep: Even if you are wearing earphones or headphones, make sure you are not near any dogs that are sensitive to beeps.
You can do any of the following, either alone or in combination:
Change the frequency. If it’s a beep, that usually means turning the volume down.
Change the period. If the beep is short, you would normally make the beep longer, which is counterintuitive but fits with the location challenge listed above.
Try not to be too abrupt. It is entirely possible to change the sound to have a more gradual start.
Don’t be too “pure”. That means adding frequencies or changing the timbre in other ways. You can add frequencies digitally, or you can use more natural sounds, like a recording of a flute in the same range as the beep. One dog I rescued couldn’t stand the sound of a flute, but could tolerate an oboe. For this recording, I used a recording of a harpsichord, altered to be pitched a little higher (it has a lower frequency than the other sounds, to make it easier for the human ear to distinguish between a digital beep and a harpsichord).
Please wear a mask. “Hide” the sound with a white noise mask, then gradually remove the mask with each recording. In this recording, the beeps are audible under the mask, but you could start at an inaudible level. I wouldn’t do this for beeps, but masking works great for broadband noises like engine roars or door slams.
Filters are also great tools. Alone or in combination, there is even more variety in sound editing. Check out this screenshot showing some of the options in Audacity sound freeware. Not all will serve your purpose, but many of the options are usable.
Back to the original sound
So we found a starter sound that doesn’t scare your dog. We can condition your dog to predict great things. So what happens? It’s not the sound your dog was scared of. But since we’re dealing with digital sounds, it’s just a matter of math to get it back to the original sound. Gradually change the sound to get closer to the original sound. This is the same as starting quietly and increasing the volume. Also, if you make multiple category changes to a sound, it may take more changes to get it back to the original sound.
I use Boldness Edit the sounds. If you have a musical background you are best suited for this task, but I think anyone who can identify pitch and timbre and is comfortable with technology can learn to create a series of sounds in this way.
High fidelity digital sound
If your dog is scared of digital sounds but not natural sounds, there is an advantage to that: digital devices can reproduce such sounds very well. I mentioned above that speaker output has a cutoff at 20,000 Hz. There is no reason for human speakers to reproduce frequencies higher than that (some audiophiles might disagree, but that’s beside the point). All sounds rendered by consumer devices, digital or otherwise, will be missing those frequencies.
Natural sounds contain high frequencies (and infrasonics) that cannot be perfectly reproduced by speakers. Digital sounds, however, can be reproduced very well for dogs. If your dog is afraid of the sounds of your smartphone, you can record that sound and play it back on your smartphone (and its derivatives). Being able to reproduce the sound accurately is a big advantage over, for example, trying to accustom your dog to the sound of thunder using speakers.
Related Research
These ideas are my own, and I don’t know anyone in the dog world who uses sound training in this way, but this method is completely consistent with what we already know about behavioral science and bioacoustics, so it’s not “new and different.”
After I started implementing this method, I found several research papers that described successful desensitization to sounds using variables other than volume. One was by Poppen (1970). In this experiment, rats were taught to associate a 3700 Hz sound with an electric shock. They were then exposed to a much lower sound (400 Hz) that did not involve a shock, and then returned to 3700 Hz in five stages. Some of the rats were exposed to desensitization only, and some were also counterconditioned with food. Both groups “unlearned” the behavioral fear response, but the counterconditioned rats unlearned more quickly. (This experiment used conditioned inhibition, which I won’t discuss here, but it allowed the scientists to measure fear acquisition and extinction.)
Scientists have done it. So have I. Zani was diagnosed with clinical sound phobia and was being treated by a veterinary behaviorist. After stabilizing his condition with medication, I conditioned him. I’ve embedded Zani’s “before and after” video here. In part 2, I will present a mini case study explaining what I did, including a list of the sounds I used and videos showing exposure to many of the sounds.
NOTE: I’ll go into this in more detail in my next post, but I’m no longer accepting clients for this work. However, I want people to know that it is doable under careful and controlled circumstances, and I will be providing more resources.
Related article
References
Barber, AL, Wilkinson, A., Montealegre-Z, F., Ratcliffe, VF, Guo, K., & Mills, DS (2020). Comparison of hearing and auditory function in dogs and humans. Comparative cognitive behavioral review, 1545-94.
Fay, R. R., & Wilber, L. A. (1989). Hearing Data book of psychophysics in vertebrates. Hilfe Associates.
Götz, T., & Janik, V.M. (2011) Repeated elicitation of the acoustic startle reflex sensitizes subsequent avoidance behavior and induces fear conditioning. BMC Neuroscience, 12(1), pp. 1-13.
Poppen, R. (1970). Counterconditioning of conditioned inhibition in rats. Psychology Report, 27(2), 659-671.
Copyright 2023 Eileen Anderson
