What is a BAHA ?
The BAHA is a unique implantable device that helps people with conductive or mixed hearing loss. It can also help people with deafness on one side.
Figure 1 BAHA device consists of an implantable titanium post (left) and the hearing processor.
How the Device Works
This device uses a technique called direct sound conduction. There is a titanium fixture that is implanted directly into the skull that provides sound by bone conduction through the bone to the inner ear. This system does not require use of the ear canal and middle ear structures. The sound transmission for the BAHA is superior to that of a standard external bone conduction device, which must transmit sound through the skin and then into the bone.
Figure 2 BAHA transmits sound directly through the bone to the inner ear
Who May Benefit from the BAHA?
Single-sided deafness – Patients may lose hearing on one side completely for various reasons. The BAHA can be implanted on the deaf side. The sound is transmitted to the good ear on the other side directly through the bone without the need for wires or ear molds. This device can help patients hear sounds coming from the deaf side without having to turn their heads. It may also improve their ability to hear in noisy situations.
Chronic ear infections – Some patients with chronic ear infections cannot wear a standard hearing aid since it may worsen the infection. Since the BAHA is implanted behind the ear and does not require use of the ear canal, it is an ideal device for use in these cases.
Congenital ear malformation – In some patients with congenital ear canal and middle ear malformations (congenital aural atresia), the hearing function cannot be restored by reconstructive surgery. A hearing aid may not be usable because the ear canal is abnormal. The BAHA can allow these patients to hear in most cases.
What is the Evaluation Process?
Patients with hearing loss undergo a full ear, nose and throat evaluation in addition to testing such as an audiogram and imaging such as MRI. Based on the medical evaluation, the treatment options for the hearing loss will be presented to you. Those who are possible candidates for the BAHA can try out the BAHA test device which simulates the sound of the BAHA.
The procedure is an outpatient surgery that takes about an hour or less. It can be performed under local or general anesthesia. In some cases, especially in children, the surgery may be performed in two stages. The surgery consists of preparing the implantation skin site behind the ear, placement of the titanium implant, and placement of the dressing.
After Surgery Care
The dressing is usually removed after a week. The patient provides local wound care at home with application of antibiotic ointment to the site. After a 3 month healing period, the hearing processor can be placed onto the titanium fixture for use. The patient may place and remove the hearing device at any time. The patient may bathe and wash his or her hair in the usual fashion.
The BAHA can be implanted in kids as young as 5 years old. The surgery is usually performed in two stages. During the first surgery, the titanium implant is placed and left completely under the skin to heal for 6 months. During the second surgery, the opening is made in the skin to allow the implant to be fitted with the hearing processor.
Figure 3 The titanium implant after healing is complete.
Figure 4 The hearing processor is attached and can be covered by your hair.