There are many different types of hearing aids to choose from. If you're getting ready to take the plunge and invest in your first sound-amplifying device, here's what you should know about the most common styles.

Complely In-the-ear

As the name implies, these hearing aids are placed completely within the ear canal. They are usually molded to fit the wearer's ear, and they are effective for mild to moderate auditory loss. These are the smallest available on the market, and as they are completely hidden inside the ear, many patients prefer them. Because the ear protects the deeply imbedded device, they are less prone to picking up wind noise. However, their small size makes them difficult to adjust for some people, and their tiny batteries need to be replaced more often than the batteries in other types of hearing aids.

In-the-canal

Like in-the-ear models are custom-molded, small devices are fitted inside the patient's ear canal, although they are not inserted as deeply as in-the-ear devices. This allows them to include some helpful features, but the small size of the aid makes it difficult to access. These devices may not sit well inside smaller ears, but like in-the-ear models, they are easy to use while talking on the telephone because they are so unobtrusive.

In-the-ear Full Shell

The device is contained in a large shell that sits inside the bowl-shaped outer part of the wearer's ear. It works for mild to severe hearing loss, and although it's more visible, it is easy to adjust. These also contain some helpful, easily accessible features like volume controls. Because their batteries are quite large, they last a long time and are easy to replace.

In-the-ear Half Shell

Unlike full shell models, which are fitted inside the entirety of the user's outer ear, the smaller half shell ones are custom-molded to sit in the lower half. This makes them something of a happy medium between larger, more visible devices and tiny in-the-ear devices. They are effective to combat mild to moderate auditory loss, and they are easier to handle and adjust than in-the-canal or in-the-ear models. They generally contain helpful features such as volume control and directional microphones.

Behind-the-ear

These hearing aids are contained in a small plastic case that rests behind the user's ear and can be easily adjusted. The device picks up sound and transfers it to a plastic mold that sits inside the outer ear. This type of aid is commonly used on children because it fits so many ear mold types, so it does not need to be replaced as the child grows. These are usually extremely visible, but they are capable of great amplification.

Open Fit

A smaller, less visible form of behind-the-ear devices, these also sit behind the ear. The device is connected to a small speaker or dome inside the ear canal via a small tube or wire. These aids leave the ear canal unplugged, so they're best for people who are only suffering from the loss of moderate to high frequencies.