He's got ears--they hear, and he talks with them, and they can tell his temperature, and at times they make a good handle.
Horses have an extremely good sense of hearing. Little is actually known about how they hear, but it is suspected his hearing is more similar to, than different from our hearing.
Humans hear a range of sounds from 30 to 19,000 hertz. Horses can hear a range of 55 to 33,500 hertz. So a human can hear a few lower sounds, but horses hear many more sounds through the higher frequencies.
While their hearing is very sensitive, it is not very precise. The horse may pick up a strange sound, but since he has difficulty placing its exact location, he "spooks." Spooking is actually just getting ready to "get the heck out of here just in case what I hear wants to eat me." Horses share this trait with other animals of prey; predators, on the other hand, can pinpoint a sound's location.
While working around horses keep in mind he will not hear you if you talk in a very low pitched voice. At the same time, he may hear high range sounds you don't hear, and he may spook, perceiving the noise as threatening.
The tone of voice you use tells your horse plenty. An uncertain tone allows him to ignore you and disobey. A definite and steady voice tells him you mean exactly what you say.
A lot of sounds are extremely irritating to some horses; clippers, for example. An irritating noise can actually cause a horse to lose his ability to concentrate on the performance you are requesting. Your horse may, for example, be perfect in the warm-up arena, but distracted by the organ music at the main show arena. Exposure to such noise, plus your calm reassuring voice can help the horse to get over the fear.
A horse talks with his ears by moving them about and telling you exactly what he is concentrating on. A horse's ears are forward, back sideways, but almost always active.
A horse's ear points at what he is looking at. (More later about how he sees in two directions at the same time.) If both ears are pointing forward, the horse is very attentive to something he sees. If his ears are casually moving about, he is relaxed and just checking things out. If his ears are nearly flat on his head, he has "sour" ears and dislikes his companions, his rider, or what he is being asked to do.
Be very careful around the horse which puts his ears flat back on his head. He is about to bite you, kick you, or he is telling you not to mess with his ears, they hurt.
A horse's ears are normally very cool. But when the horse is not feeling well and has a temperature, you'll be able to "feel the heat" in his ears. Luckily horses don't have a lot of problems with their ears, says Dr. Alice.
One of the most common discomforts a horse suffers is infestation by ear ticks. These parasites invade the ear canal, becoming extremely irritating. The horse will shake his head, but to no avail. He'll lay his ears back and he'll resent anyone touching the ear.
There's no way you're going to get the ear ticks out, so call a veterinarian, says Dr. Alice. The vet will provide a medication to kill the ear ticks.
Wax buildup in the ear is also very uncomfortable for the horse. Ear wax can be dissolved with cerumenolytic agents, which can be provided by your veterinarian.
A lot of horses get flat, gray warts in their ears. These are persistent, but usually don't bother the horse too much. Treatment for such warts is usually not recommended, Dr. Alice said. (In most cases these warts are more troublesome to the horse's owner than they are to the horse.) Sarcoids are relatively common, as are melanoma on or in the ears of gray horses.
The tips of the ears are often frozen off horses that are pastured in extremely cold areas. Foals born in the high country often lose the tips of the ears due to frostbite. The tips of the ears are generally the last part of the new foal to dry and are, therefore, susceptible to the cold. And the ears are very subject to wounds. Split-eared horses are a pretty common sight. Such splits can usually be repaired with cosmetic surgery. Even splits several years old can be repaired by a skilled vet, says Dr. Alice.
There are several conditions that do not involve the ear itself, but which may affect the horse's hearing.
Parotitis is swelling and inflammation of the parotid salivary gland, just below the ear. With parotitis, the horse isn't going to like you fooling with his ear.
Diseases of the guttural pouch can also cause a swelling beneath the ear. The guttural pouch is peculiar to the horse. It is a sac that opens into the Eustachian tube of the inner ear, Dr. Alice explains. It can become infected; sometimes with foals it distends with air, causing a condition known as tympanitis.
Tympanitis and parotitis both need the attention of a veterinarian. Finally a horse's ear makes a good handle if it is necessary to restrain a horse. Mistakenly a lot of people claim "earing" a horse will make the horse ear-shy. If done properly, "earing" is a satisfactory method of restraint which will leave no ill effects.
Attacking a horse's ear suddenly, or trying to pull the ear off, will make a horse ear-shy.
But if the ear is grasped gently, then intermittent and powerful pressure is applied with the fingertips, and the ear is released slowly, the horse will show no signs of "shyness."