BAHA, short for Bone Anchored Hearing Aid, is a surgically implanted hearing device that bypasses the auditory canal and middle ear, relying instead on direct bone conduction to transmit sound. It consists of a titanium implant, an external abutment and a sound processor. The sound processor transmits sound vibrations to the implant, and the bones of the skull work as pathways, forwarding those vibrations to the inner ear, where the nerve fibers that allow hearing are stimulated.
The BAHA system has been in use since 1977, and is an FDA-approved alternative for treating conductive, mixed, and unilateral (one-sided) sensorineural hearing losses. It is especially helpful for people who suffer from chronic ear infections that cause hearing loss. In these patients, conventional in-the-canal hearing aids are ineffective because the resulting humidity and fluid buildup aggravate the condition. Other candidates for BAHA include people with congenital ear defects such as narrow or absent ear canals and those with single-sided deafness that has resulted from surgery or a tumor.
Older bone conduction hearing systems required the patient to wear an uncomfortable steel spring headband, and sound quality was poor because the skin acted as a barrier that prevented sound vibrations from reaching the inner ear. In addition to a much more comfortable fit – the device is placed behind the ear, eliminating the need for a headband – the BAHA system’s skull bone implantation translates to improved hearing in noisy situations and the ability to localize sounds, while producing a more natural sound and speech clarity with minimal feedback or distortion issues.
The surgical procedure is safe and effective and carries little risk of complications or side effects. It is typically performed on an outpatient basis using a local anesthetic. Eventually, the titanium implant fuses to the skull bone through a process known as osseointegration.