Dogs hear better than humans, that's a fact that has been known for some time, but it this really true? Better hearing explains why your dog is barking apparently at nothing in the evening while you are scratching your head wondering what in the world he's barking at.
Just because you don't hear sounds though doesn't mean they aren't there, so before putting your local paranormal experts on speed dial to get rid of ghosts in your home, consider that your dog may be barking simply because he is hearing things that you simply cannot hear.
A Lesson in Comparative Anatomy
Comparative anatomy is the technical term used to depict the differences and similarities in the anatomy of different species. When it comes to comparing a dogs' and humans' hearing, it therefore comes helpful taking a closer look at those ears and their fascinating characteristics.
Dog ears are known to be blessed with more than 18 muscles. These muscles allow dogs to swivel their ears in various directions, similarly to satellite-dish antennae, which helps them orient and locate the origin of sounds.
Humans, on the other hand, have only six muscles with limited mobility with the exceptions of those folks who are capable of wiggling their ears.
On top being capable of swiveling, a dog's ears are very potent. Dogs are estimated to hear in frequencies up to 60,000 hertz, while humans hear only up to 20,000 hertz.
A dog's hearing is estimated of being capable of detecting and distinguishing sounds approximately four times as far as humans. "This means what a human can hear at 20 feet a dog can hear at roughly 80 feet," points out Marc Bekoff in the book "Canine Confidential, Why Dogs Do What they Do" when referencing an article by Service Dog Central.
This explains why humans have relied on dogs since ancient times. Since dogs can hear better, they have helped humans for centuries by alerting them to potential dangers that humans couldn't detect.
A Dog's Evolutionary Past
So why do dogs hear better than humans? Why can they detect high-pitched sounds that humans cannot detect? Why were they blessed with such an advantage? It all boils down to the dog's evolutionary past.
The capacity of detecting sounds at higher frequencies stems from a dog's hunting needs. Before being fed bags of kibble served in shiny bowls, a dog's small canid ancestors relied on hunting down a variety of critters for dinner.
Part of these critters on the menu may have included mice, voles and rats. These prey animals are known for emitting high pitched squeaks along with the production of high-frequency crackling sounds as they move around dry leaves and grass, points out Stanley Coren, in the book "Do Dogs Dream? Nearly Everything Your Dog Wants You to Know."
The ability to detect high-frequency sounds emitted by such critters therefore provided a survival advantage. In cats, this capability is even more pronounced considering their past dependence on rodents for nutrition. It is estimated that cats may detect sounds that are 5,000 to 10,000 Hz higher than dogs.
Detection Over Resolution
While dogs can detect sounds better and farther than humans, there is often some sort of trade off going on. In most animals, detection is emphasized over resolution.
This means that many animals are prone to responding to something long before they know what exactly they are dealing with. This explains why dogs often adhere to the "bark first, inspect later" philosophy.
In a world where you must search for dinner and at the same time avoid becoming dinner, the ability to respond quickly to sights and sounds is an important survival trait.
For instance, when it comes to vision, dogs may easily detect movements with their eyes, but they cannot see the fine details as our eyes can. When it comes to hearing, dogs may easily detect sounds, but when it comes down to fine details, such as distinguishing similar sounding words, they may encounter difficulties. Humans, as verbal beings, fair better in this department.
"Our brains are probably much better than dogs' brains when it comes to distinguishing very similar sounds, a skill we've evolved to in order to decode speech."~John Bradshaw, Dog Sense, How the New Science of Dog Behavior Can Make You a Better Friend to Your Pet."
Now That You Know...
By better understanding how your dog hears, you can take some steps to make his life a little better. Following are some interesting facts, tips and ideas.
- Consider that your dog's ability to detect higher frequencies may affect his life in your home. Vacuum cleaners, power tools and motorized lawn mowers emit high-frequency shrieks that can cause significant distress in dogs. DVD players and DVRs tend to also create annoying fan noises which be particularly irritating to dogs.
- It may help to turn off electronic devices at the plug when not in use.
- Create a "safe haven" room away from electronics and led lights.
- When dogs are kenneled in busy boarding facilities, they may suffer from the effect of exposure to many high-frequency sounds such as those produced by the banging or metal gates and clanging of metal buckets.
- Pick your dog's name wisely. While dogs are capable of detecting tones that are very low or high, they aren't very good in discerning similar sounding words. For instance, if your dog's name is Milo and your son's name is Shiloh, he may have a hard time distinguishing his name from your sons'.
- However, according to a recent study, dogs appear to have decent abilities in recognizing their names in noisy environments even in presence of background noise made by several people talking at the same time (cocktail effect). Dogs who work closely with humans were found to be more adept in this compared to the average companion dog.