Single-sided deafness is a special case of deafness that often goes unrecognised. Hearing loss in one ear may happen following an ear infection, head trauma, ear tumours, blockage of the ear artery, pressure build up in the ear; or for unknown reasons.
One-sided hearing loss causes a loss of stereophonic sound and the inability to determine where the direction of sound is coming from. Furthermore, a patient with single-sided hearing loss has a lot of trouble hearing when there is background noise and during social situations.
Treatment options of single-sided hearing loss include:
The CROS hearing aid receives sound on the deaf side and then, via either wired or wireless technology, sends the sound to the good ear (which is fitted with a hearing aid).
Bone Anchored Hearing Aids (BAHAs) are designed for people with either conductive or mixed hearing loss; and for people with complete single-sided deafness.
The BAHA sends sound via vibration, through the skull, to the good ear. No hearing aid is required to be placed in the good ear – the sound reaches the good ear via the vibrations sent through the skull and brain.
The Cochlear BAHA (Figure 4) uses direct bone conduction, which is a natural pathway for sound. A small titanium implant is placed in the bone behind the ear. The patient’s own bone then grows into the implant and allows any sound energy to be directly transferred to the inner ear, with very little loss of sound energy. The result is often crystal clear sound with no feedback or whistling.
An external processor captures sound via the microphone and converts the sound to vibrations. The vibrations are sent directly to the bone through the implant. The sound travels to the inner ear, bypassing the outer and middle ear. The motion causes the fluid inside the cochlea to move the hair cells. The hair cells change the movement into electrical impulses that excite the hearing nerve; and the brain processes this as sound.
1. Conductive Hearing Loss
People who have a problem with the sound conduction mechanism (ear canal, ear drum and/or ear bones) are excellent Cochlear BAHA candidates.
2. Mixed Hearing Loss
When there is a combination of conductive hearing loss and mild nerve deafness (sensorineural hearing loss), you may be a good candidate for BAHA, provided your good ear has normal hearing.
3. Single Sided Deafness on one side and normal hearing on the other side.
When there is a complete loss of hearing on one side and normal hearing on the other side, the Cochlear BAHA is potentially a very good option for hearing on the damaged side.
On the day of your implant surgery, your surgeon will meet with you before the operation to run through the details of what to expect during and post-surgery.
The operation typically takes about one hour to perform. The surgery may be performed under local or general anaesthetic; and it is common to go home from the surgery on the same day. More than 50 percent of Northside Audiology BAHA patients will say they have little or no pain during the procedure.
Approximately six to eight weeks after surgery, you will return to Northside Audiology for the ‘switch-on’ of your new hearing device. The device is attached and programmed on the day; and usually clear, useful sound is heard instantaneously.