Exposure to high levels or extended periods of sound can result in something called NIHL -- or Noise Induced Hearing Loss -- in dogs. This danger is especially real for military, police, search and rescue, service, and hunting dogs, all of whom are exposed to a wide range of both sights and sounds throughout the course of their day.
For both the working dog and the handler, a dog’s hearing is an essential element of safety. Working dogs need to be able to take in their surroundings and hear commands, but when dogs suffer from NIHL they can’t do this as well, thereby putting everyone in danger. Similar to humans, dogs can get NIHL from any form of prolonged loud noise like truck or helicopter transportation, gunfire, or even a loud nearby construction site.
That’s why Rex Specs partnered with Zeteo Tech and Dr. Peter M. Skip Scheifele, PhD - a leading animal audiologist in the United States - to help create dog hearing protection for the military, active working dogs, and your everyday adventure pup. To answer all your dog hearing questions, we talked to Dr. Scheifele directly. Here’s what he had to say.
(Responses have been edited for clarity and efficiency.)
What Is Noise Induced Hearing Loss (NIHL)?
Noise induced hearing loss is what happens to the ear if it is exposed to prolonged sounds that are within the range of the animal’s hearing frequency and is loud enough to cause the stereocilia, which are the top of the hair cells in the inner ear, to fatigue. They (the stereocilia) will eventually fatigue to the point that they will not operate anymore, therefore the brain cannot get any sound from the ear.
How Do You Tell if a Dog has NIHL?
We run an actual audiological test called a BAER test – we call it a bear test even though it's not spelled like bear. This is an electrophysiological test that tells us what the dog’s hearing threshold is in each ear. Hearing threshold being defined as what level does the dog actually hear the sound at the time of testing..
Generally we run these on puppies and when we run a BAER screening test on a puppy, we put in a very loud sound to the ear that the ear should absolutely be able to hear. If the dog's ear and brain is not reactive to the sound then that puppy is deaf.
In an older dog, we would run through a series of different intensities and wherever the intensity stops – where the waveforms no longer conform to one another, then we know that the dog can hear up to that point but not afterward.
What are Some Situations in Which a Dog May Experience NIHL?
There are actually many situations. But the bottom line is any kind of noise that is prolonged and intense within the frequency range that they can hear can cause hearing loss. For example, dogs that are kenneled (larger kennels in shelters, or in working dog environments that are typically not built to dampen sound) are exposed to the noise of barking, etc. Dogs that are shot over, or exposed to gunfire regularly - like hunting dogs - may experience NIHL. Even dogs that are kept in situations that are very noisy outside of the homes. Any of those things can cause a hearing loss.
What are the Problems that Can Occur from NIHL?
Obviously if the dog becomes deaf then there will be issues that have to be resolved with behavior of the human as well as the dog. If the dog has hearing loss whether it's mild, moderate or certainly severe, the dog won't respond to the owner as quickly, the dog may appear to be very confused, or the dog may not be able to localize where the sound is coming from. So all of that causes some problems when working the dog and having the dog understand what a human handler is trying to communicate to it.
How Does Dog Hearing Protection Work?
The hearing protection device for the dog works similarly to hearing protection devices for humans. The Ear Pro covers the ears, and is more or less impervious to whatever sounds are outside of the hearing protection. The technical, stretchy fabric and acoustic foam that the device is made of helps keep the ear pro tight to the dog's head forming a good seal around the ear. In audiology we use the term attenuated, or dumbed down, even eliminated to describe what happens to sound when it tries to pass through sound blocking materials. The goal of the hearing protection is to attenuate as much noise as possible - reducing stereocilia fatigue, reducing noise induced hearing loss.
Why Were These Developed Specifically for Military and Working Dogs?
These hearing protection devices were originally created for the military. The amount of training these working K9s do under noisy conditions, the kenneling environment - where you may have as many as 100 dogs in a kennel, transportation noise in helicopters or fixed wing aircrafts, or gunfire can have long term effects on a dog's hearing. All of these can reduce the dog’s ability to hear, thereby reducing the ability of a dog to continue working.
Lastly, military members, Police Officers and SWAT team members are heavily dependent on their dog’s ability to perform at its potential. We want the dog to be able to hear as well as it possibly can for the sake of not only the dog, but also for the safety of the handler.
What Situations Would You Recommend a Non-Working Dog Have Hearing Protection?
There are countless situations that non-working dogs could benefit from hearing protection - these include:
- Hunting - repetitive gunfire exposure
- Transportation in airplanes, trucks, and other vehicles where there is engine noise exposure
- Loud outside environments, such as concerts or around construction
- Holidays where dogs could experience noise from fireworks, parades, etc.