Single Sided Deafness, Bone Anchored Hearing Aids (BAHA), and Cochlear Implants
Those individuals who suffer a severe hearing loss in one ear where the other ear is otherwise normal or relatively normal often find difficulty managing in the community. Particular problems include difficulty with localisation of sound and hearing in background noise.
Traditional options for hearing rehabilitation include a biCROS hearing aid or a Bone Anchored Hearing Aid (BAHA). The basic principle is to reroute a signal from the non-hearing ear to the hearing ear giving the illusion of binaural hearing.
In more recent years, cochlear implantation has become a very attractive option in the management of single sided deafness in selected patients. It is the only option that allows restimulation of the dead ear which provides optimal tinnitus control and true binaural hearing. It is highly motivated patients, especially those who are often in a demanding audiologic environment that gain the biggest benefit of a cochlear implant over a BiCross or BAHA. Both the Cochlear and Medel implants are now TGA approved for use in single sided deafness.
A Bone Anchored Hearing Aid involves the implantation of a pure titanium screw behind the ear to which is attached a hearing aid or sound processor. This is termed the BAHA connect. This allows transmission of sound through the skull to the contralateral good ear. The other indication for a BAHA is for ears that have good residual nerve function but for various reasons are unable to be surgically reconstructed or are unable to wear a standard hearing aid. The BAHA attract allows the placement of a subcutaneous magnet, that in selected cases avoids the need to have a transcutaneous abutment. The Bonebridge is another bone anchored hearing aid option that is placed subcutaneously and is attached to the sound processor magnetically. It is a so called active bone anchored hearing aid.
The Department at St Vincent’s Hospital were one of the first units inserting Bone Anchored Hearing Aids and to date has performed more of this procedure than any other unit in New South Wales. The department was involved in a trial prior to the introduction of the BAHA Attract system.
Prior to consideration of surgery a trial is performed, which involves attaching hearing aid via a head band, allowing a patient to assess the degree of improvement in hearing.
The surgery itself is a day surgery procedure with the linear incision technique used for the BAHA connect, which limits complications and accelerates healing. A 3 week period is required for the pure titanium screw to osseointegrate into the skull. After this time the hearing aid may be fitted. The BAHA attract is inserted completely under the skin and requires a semicircular skin incision behind the ear.
If you would like more information regarding this procedure or single sided deafness please contact one of the members of the department.