Styles of Hearing Aids
There are many different styles of hearing aids to choose from. Determining which style is best for you depends on multiple factors, including:
- Type and severity of hearing loss
- Visual and dexterity abilities
- Cosmetic concerns
- Features and controls needed
- Size and shape of ear
Behind-the-Ear (BTE) Hearing Aids
Behind-the-ear (BTE) aids consist of a small plastic case worn behind the ear. The circuitry of the hearing aid is housed in this plastic case, which is connected by a clear tube to an earmold. The earmold is a custom-fit piece that delivers sound into your ear. Some advantages to this style include increased power for more severe losses, decreased whistling (feedback) in some cases and less of hearing aid damage for those with excessive earwax or drainage from the ear.
Open-Fit BTE Hearing Aids
Open-fit BTE aids are similar to the traditional BTE aids in that the plastic case rests behind the ear. The main difference with this style is that instead of a custom earmold, a thin tube connects to a small dome that fits in the ear. This type of hearing aid may be appropriate for those with normal hearing at some pitches but hearing loss at other pitches. It may allow you to utilize some of your natural, normal hearing while amplifying only those pitches where you have hearing loss. This may reduce the perception of feeling "plugged up."
In-the-Ear (ITE) Hearing Aids
In-the-ear (ITE) hearing aids are custom made and fit entirely in your outer ear. All of the hearing aid circuitry is contained inside this one-piece, which fills the bowl of the outer ear. While these aids can be smaller than BTEs, they can usually fit many of the features, such as volume control, directional microphones, and telecoil, to name a few. The sizes of these aids, however, can limit their power output and therefore are not appropriate for severe to profound hearing loss.
Canal Hearing Aids
Canal hearing aids are the smallest custom-fit hearing aids. In-the-canal (ITC) aids fill the entire ear canal, while completely-in-the-canal (CIC) aids are even smaller and sit further down in the canal where they are almost hidden. This style has many cosmetic advantages due to their small size. However, they may be limited to how many special features can be added due to their small size.
Other Hearing Aid Considerations
When traditional hearing aids are not an option, there are a few special hearing aids that may be a more appropriate fit: CROS, Bi-CROS and Baha.
The CROS/Bi-CROS system differs in function compared to traditional hearing aids. Depending on the circumstances, a traditional set of hearing aids may not be the most appropriate recommendation. Single-sided deafness, poor word discrimination or unaidable hearing loss in one ear are some instances in which the audiologist may recommend an alternative option to help address hearing health concerns. These options may include a CROS or a Bi-CROS system.
A CROS system consists of a transmitter (worn on the poorer ear) and a receiver (worn on the better hearing ear). Cosmetically, it does appear as though a set of hearing aids are worn. However, the difference is in the function of the device. With a CROS system, incoming auditory information from the poor ear transmits the acoustic signal to the better hearing ear. A Bi-CROS system works similarly to the CROS however, identified hearing loss in the better hearing ear is taken into consideration during programming of the device.
Baha Hearing Aid
A bone-anchored hearing aid, also referred to as a BAHA, is a surgically placed device that can be beneficial to people for whom a traditional hearing aid may not be appropriate. Someone with single-sided deafness, a mixed hearing loss or a conductive hearing loss may be a candidate for this type of hearing aid.
The Baha works by sending sound directly through the bones of the skull. A sound processor is attached to a titanium screw that is surgically implanted in the temporal bone. Sound is picked up by the processor which in turn sends auditory vibrations to the screw. The sound will travel through the bones of the skull and cause vibrations of the fluids in the inner ear. These inner ear vibrations are then transmitted via neural impulses and are perceived as sound. This process allows sound to bypass the outer ear and middle ear, which is why this device usually works well for those with conductive hearing loss.
In the case of those with single-sided deafness, the vibrations of the skull are picked up by both inner ears (cochleas) and therefore allow sound to bypass the poorly-functioning cochlea and be picked up by the functioning cochlea. This does not return hearing on the deaf side; instead the screw and processor are placed on the poorer-hearing side and sound is sent through bone conduction to the better hearing cochlea. This may allow the user to listen to conversation on their poor side without turning the head.