I asked Lyn, Chair of Baha Users Support and Honorary member of The Baha Professionals Group, about her Baha hearing aids. Here she very helpfully explains what a Baha is and how it differs from an air conduction aid – which I’m guessing most of us wear as the BTE (Behind the ear) is what I see most people wearing.
For me, having Bahas means the difference between having no useful hearing, to having hearing that “is” useful.
Putting my Bahas in on in the morning is like opening double windows to sound.
Like all aids they have their limitations, the range of sound is not “normal” but it enables me to communicate mostly effectively, assisting my lipreading.
I see my bilateral Bahas as offering me “effective” hearing for longer than I would otherwise have it, as my nerve hearing is now failing on one side. I cannot use any other type of hearing aid.
My middle ear parts don’t work, the middle ear consists of the ear drum and the little bones behind it. So the chain of sound is broken, there is nothing to carry the sound from the outer ear to the inner nerve part of the ear.
The Bahas are sound processors which attach to an abutment (socket) behind my ears. The abutment is held on to the skull by a tiny 4mm titanium screw fitted into the bone. A 40 minute minor surgical procedure, usually a day case job under local anaesthetic (for most adults).
The Baha can be used as a regular bone conduction aid in children from a few weeks, or attached to an elasticated material headband called a Softband.
This enables use from an early age without causing any deformity of the young bones, as happens with the usual headband type. The implant can be fitted when the child’s skull is mature enough.
The sound processors pick up sound, convert it to vibrations (as would normally happen with the middle ear parts), the vibrations are carried to the skull bone via the abutment and tiny titanium implant screw.
Bone is an efficient conductor of vibrations, and the vibrations are carried directly to the cochlea (inner nerve part of the hearing mechanism).
Some people can be profoundly deaf conductively (due to middle ear problems) but can have perfectly working nerve hearing parts. So the Baha is a very effective “middle ear bypass”. The better the cochlea function the better the benefit from the Baha. Only an assessment by audiologists trained in Baha can tell if a person is suitable and can benefit – the Baha is available on the NHS, though the funding is very inconsistent round the UK!
It can also help people who are single sided deaf, even if their deaf ear is nerve deaf (as in post acoustic neuroma surgery). The Baha enables sound to be picked up on the deaf side, and the vibrations are heard in the working nerve on the opposite side of the head, offering a “sense” of bilateral hearing.
Mostly the Baha is fitted to people who can benefit, and who are unable to use air conduction aids.
This could be due to deformities of middle or outer ear parts, or in many cases due to middle ear disease / infection where there is damage to the little bones and no hope of reconstruction surgically (as in stapedectomy).
Also people with middle ear disease / infections can have their problems made worse by blocking off the ear canal with air conduction ear moulds.
I personally could only wear my air conduction aid for 20 minutes before the middle ear would start weeping. So I kept it in my handbag, and only put it in when I “really” needed it…. because of the middle ear destruction the air conduction aid did not offer me very effective hearing anyway.
Now my Bahas offer me 24/7 optimal hearing. Hearing that is consistent, even if I have middle ear infections.
Thank you for “listening”. Lyn.
* Pictures courtesy of Cochlear, the manufacturer of the Baha.