This horse has one ear on the photographer and the other  swiveled to listen to a donkey bray. Many horses find donkey sounds unnerving.

Kathy Lundberg | Contributor

The Fourth of July is a time to celebrate our great nation. For many people, this means attending a community fireworks display, or shooting a few off at home.

Hopefully, any fireworks are set off at a safe distance from barns, due to fire hazard. Even when they are far away, fireworks can be loud enough to scare a usually calm horse into a worried frenzy.

Horses have a good sense of hearing. They hear all the sounds we hear, plus about another half octave higher. Their ears can swivel 180 degrees, independently of each other.

The ear is made of stiff cartilage, and is funnel shaped. Its shape channels the sound from one direction, shielding and diminishing the background noise.

Horses’ ears have soft short hairs on the outside, which lie flat, like on the body in general. The hairs inside the ear are longer and stiff, and do not lie flat.

Some horses and ponies get exuberant tufts of hair coming out near the base of their ears reminiscent of an old man in need of a trip to the barber. These hairs help keep insects out, and also act as sensory devices.

The slightest touch on the ear hair generally triggers a reflex whereby the horse flicks its ears or shakes its head, serving to dislodge small, unwelcome intruders. We work with horses to overcome this instinct so that we can get the bridle over their heads, put on fly masks or clean their ears. Some people clip the ear hair for a neater look in the show ring.

The ear canal continues on from where we see it disappear straight down into the head for a couple inches, then changes direction horizontally, as it proceeds toward the brain. The inner workings of the ear are similar in all mammals, even if they look quite different on the outside.

The ear canal ends at the ear drum. Behind this is the middle ear with its three little bones: the hammer, the anvil and the stirrup, named after their shapes. The inner ear has three tiny fluid filled loops oriented in different planes, which help the animal determine up from down. The cochlea is the snail-shaped organ that actually transmits the sound wave into a signal which the brain can understand.

How well an animal hears depends on how well it needs to hear. Horses need to know if a predator is sneaking up on them. Their sensitive hearing makes them averse to loud noises. Horses in competition often use earplugs of to dampen sound so they can stay focused on the matter at hand.

Hearing is one thing, and localizing sound is another. A predator like a cat needs to know exactly what kind of sound is being made and where exactly it is coming from. Kitty patiently waits and gathers the information on volume, source and location so she can pounce on that mouse in the grass and obtain her meal.

Horses have keen hearing, but they have even keener eyesight. When a horse hears a noise, it generally looks to see where the sound came from. They do not need to have as precise knowledge as the cat. They need to know enough to run in the opposite direction, thereby avoiding becoming a meal. Run first, ask questions later.

These facts help us understand why horses may seem easily “spooked” or more concerned about sounds that we do not worry about. Police horses and horses used for gun sports must be taught to overcome their natural reactions to gun shots and other loud stimuli.

Some horses are more reactive than others. Arabians tend to be quite reactive; Shetland ponies much less so. Individual horses worry more than others within the same breed.

The Fourth of July will probably be accompanied by loud sounds that your horses (or your neighbor’s horses) may get worried about. A few points to consider to help keep your horses safe:

1.) Never set off fireworks anywhere close to a barn! Review your farm’s fire safety procedures; be sure you have appropriate fire extinguishers. We are emphasizing hearing in this article, but fire safety is paramount!

2.) Check your fences and facilities to be sure they are in good repair and will hold your horses.

3.) If you have any concerns regarding your neighbor’s holiday activities, share your concerns in a friendly manner BEFORE the fireworks start.

4.) Know where your horses are most comfortable. Some horses get more anxious inside the barn than outside, but outside you may have additional visual stimuli. Horses will generally feel most secure when they are together with their usual companions in a familiar place.

5.) Consider playing some gentle music on the radio in the stable.

6.) If your barn is likely to be loud, consider putting cotton in the ears of horses who get anxious. If you have a horse with a history of panicking at loud noises, consider asking your veterinarian for a sedative. Better yet, work with your horse during the course of the year to desensitize him. Some owners have gone so far as to relocate their horses during the Fourth of July to a more remote and quiet place.

Horses have sensitive ears with excellent hearing but are not as accurate in localizing sound as some other animals. This makes them more reactive to loud noises, of which the Fourth of July usually abounds.

A few simple precautions can help keep your horses safe and calm. Why are we humans so enthralled with startling sights and loud sounds in the first place?

Kathy Lundberg is a regular pets contributor for AnnArbor.com, and owner of Scio Church Stables. Email her at scs@sciochurchstables.com.