Ear bonnets are often used for several different reasons. 

An ear bonnet is not only a stylish accessory that can be matched to the saddle pad and other equipment, but also can be used to reduce noise, helping block out distracting sounds such as wind, traffic, and other noises. 

The ability of an ear bonnet to reduce noise can help make the horse calmer and more focused on the task at hand rather than on the surroundings, which is why ear bonnets are common at competitions and during training. 

Using an ear bonnet is also a good way to protect the horse's sensitive ears against flies and other disturbing insects during the warmer months.