Horses have binaural hearing meaning they hear out of both ears at the same time, the same as people and most other animals. However, unlike humans who have small, flat ears, a horse’s ears are large and shaped like a cup. These ears act like a satellite dish to capture sound waves and funnel them to his inner ear. Because of this, very little sound is missed and the horse might hear noises that you can’t. This is one reason why you may think that everything is perfectly fine, but suddenly you horse spooks for no apparent reason. He may have heard something that sounded like a predator to him.
A horse also has the ability to hear a wider range of high-frequency tones, like a dog being able to hear a dog whistle. As a prey animal, hearing acuity is a necessary form of “early warning system” from predators. Since predators rarely vocalize when stalking prey, the horse has learned to carefully listen for any sounds that a predator could be approaching – the snap of a twig, the rustle of grass. These noises contain the high-frequency sounds that you horse can then use to locate the direction from which the predator may be coming. Horses aren’t worried about pinpointing the exact location of the predator – they’re not planning a counter-attack. Instead, horses just want to know generally where they are located so they can decide which path will take them the furthest away from fangs and claws the fastest. First the horse will use his ears to pinpoint those early warnings. Then he’ll follow-up with eye movement and finally will raise and turn his head so he can better focus. During this time, the horse will stay as motionless as possible – often stopping their grazing so they can hear better.
Once the horse has determined that danger is in the area, it’s time to react. Horses have a strong emotional response (fear) to whatever sensory input they receive. This fear triggers a horse’s flight mechanism for safety. Horses aren’t brave – they won’t remember that you are sitting on their back or standing in front of them. Their only concern is survival – run first, think later.
Male horses may react more strongly to sound simply because they’re traditionally the herd watchdogs. They don’t necessarily hear any better than females do, but they feel a need to alert “their” herd to perceived danger. That’s why some horses suffer more anxiety than others at shows or in any new environment. A strange place can put your horse on high alert for danger, causing him to be emotionally aroused and to make his reaction to noise even stronger than it would be in a familiar setting. If he’s fairly “bombproof”, his anxiety may not result in undesirable behavior. If not, you may have a hard time keeping him focused in the ring and extra care should be taken when riding or working around him.
You can help reduce your horse’s ability to take in these reactive noises by blocking his ears with earplugs or thick wads of cotton. If that’s not possible, keep alert to your horse’s ears to avoid a possible spook. His ears will signal where is attention is directed – to the side at a dog, behind him at a flapping bag, etc. If you can direct his attention elsewhere, you can usually avoid the spook.
Like humans and other animals, your horse can lose his ability to detect sound as he ages. Age-related hearing loss in horses can begin at age five for horses, starting with the higher frequencies and working down the scale. High-frequency hearing loss isn’t generally obvious in horses until they reach about fifteen. But because your horse has a wider range of high-frequency hearing than a human, he can lose more of it before you notice a lack of response to sounds you hear.
Practice good ear health by checking his ears weekly for signs of insect infestation or infection. Redness, scratching, hair loss on the ear could indicate rubbing. If you suspect a hearing problem in your horse consult your veterinarian. If your horse has hearing loss, you’ll need to make some management changes for safety. These tips are actually good whether you suspect hearing loss or not, especially when working around a strange horse. Always speak to the horse as you approach, so you don’t startle him. And be sure he heard your approach warning by watching the direction of his ears: one or both should flick toward you.
Understanding how your horse’s hearing and reaction to sounds differs from humans can help you anticipate and reduce his anxiety and avoid a dangerous reaction.