Bone-anchored hearing aid

A bone-anchored hearing aid (BAHA) is a type of hearing aid that is based on bone conduction. It is used to help individuals with certain types of hearing loss, particularly conductive hearing loss, mixed hearing loss, and single-sided deafness. Unlike traditional hearing aids that amplify sound through the ear canal, a BAHA transmits sound directly to the cochlea via the bones of the skull.

File:The sound processor from Oticon Medical behind the ear.png

The sound processor from Oticon Medical behind the ear

Mechanism of Action

The bone-anchored hearing aid system consists of three main components:

1. The Implant: A small titanium implant is surgically placed into the skull bone behind the ear. This implant acts as an anchor for the external components.

2. The Abutment: This is a small connector that attaches to the implant and protrudes through the skin. It serves as a docking point for the sound processor.

3. The Sound Processor: This external device captures sound from the environment, converts it into vibrations, and transmits these vibrations through the abutment to the implant. The vibrations are then conducted through the skull bone to the cochlea, where they are perceived as sound.

File:Baha implant in hand.jpg

Baha implant in hand

Indications

Bone-anchored hearing aids are typically indicated for individuals who:

• Have conductive hearing loss where sound cannot efficiently travel through the outer and middle ear.
• Have mixed hearing loss where there is a combination of conductive and sensorineural hearing loss.
• Suffer from single-sided deafness (SSD), where one ear has normal hearing and the other ear has profound hearing loss.

Surgical Procedure

The surgical procedure to implant a BAHA is relatively straightforward and is usually performed under local anesthesia. The surgeon makes a small incision behind the ear and drills a hole in the skull bone to place the titanium implant. After the implant is secured, the skin is closed around the abutment, which remains exposed. The area is allowed to heal for several weeks before the sound processor is attached.

Advantages and Disadvantages

Advantages

• Improved Sound Quality: BAHAs provide clearer sound quality for individuals with conductive and mixed hearing loss.
• Comfort: Since the device does not occlude the ear canal, it is often more comfortable than traditional hearing aids.
• Cosmetic Appeal: The device is less visible than some traditional hearing aids.

Disadvantages

• Surgical Risks: As with any surgery, there are risks of infection and complications.
• Maintenance: The abutment requires regular cleaning to prevent skin irritation and infection.
• Cost: BAHAs can be more expensive than traditional hearing aids.

Baha user sound processor behind ear

Related Pages

• Hearing loss
• Cochlear implant
• Hearing aid
• Bone conduction

See Also

• Audiology
• Otolaryngology
• Hearing health professional