Monday, December 5, 2011

Baha (Bone Anchored Hearing Aid)


Reference information: www.entific.com.hk

The baha, as its abbreviation suggests, works by direct bone conduction of sound to the cochlea via a sound processor and titanium implant on the skull. As the sound conduction is entirely via bone conduction to the cochlea, the external pinna, external ear canal and middle ear bones are not required. In fact they are completely bypassed. Hence the baha is suitable for those without an outer ear and occluded ear canal (microtia and congenital aural atresia) and those with poor middle ear conduction problems (mastoidectomy, loss of ossicles, otosclerosis).

The baha is especially ideal for patients with one-sided complete hearing loss, aka single-sided deafness (SSD). These SSD patients experience a poor perception of sound on one side especially on the phone, during meetings and dinners, and in noisy environments. The baha “captures” sound from the deaf side, and transmits it to the only working ear on the opposite side through bone conduction through the skull. The patient is then able to appreciate sounds and conversation on the deaf side, and finds themselves once again, enjoying their sound rich social environment.

One of the greatest advantage of the baha is that it is the only implantable hearing processor that allows people “to try before they buy”. By using a soft band applicator as a connection to the skull, the baha can be tried without surgery required. If the user likes the baha, they can choose to continue using the softband approach, or undertake a more securely applied baha via a surgical titanium implant to the skull, just behind the ear. Certainly, for the surgical installed baha, as there will be no intervening soft tissue unlike the softband trial, the sound heard will be clearer after the BAHA is implanted.

The surgery is a single-stage surgery, done with a minimal invasive implantation, maximizing the preservations of tissues. It takes around 15 minutes to complete the whole procedure and can be done within a clinical setting.

The information aims to provide educational purpose only. Anyone reading it should consult ENT Specialists before considering treatment and should not rely on the information above.