Hearing implants provide solutions for children and adults with more serious and complicated conditions that cannot be solved with a traditional, external hearing aid.

Dr Johan Nell, an otorhinolaryngologist – or ear, nose and throat (ENT) surgeon at Mediclinic Louis Leipoldt, says most of his patients with hearing issues are referred by audiologists and paediatricians, with a few self-referrals.

“We work closely with the audiologists as candidacy is highly dependent on preoperative hearing assessment,” he explains.

Also, post-implant audiological support is vital, especially in cochlear implant patients. In infants with prelingual deafness, i.e., deaf from birth or before they acquired language, therapy and psychological support is necessary.

We implant two different types of devices at Mediclinic Louis Leipoldt: the cochlear implant and bone conduction devices. This type of surgery is generally very successful and the devices need not be removed once implanted

Congenital versus acquired hearing loss 

Hearing loss can be either congenital or acquired, explains Dr Nell, and for each problem, there is a possible implantation solution. 

“Congenital hearing loss presents in infants. In the first type, termed sensorineural hearing loss, the ear canal or middle ear appears normal but the cochlear [inner ear] function is affected. These patients benefit from a cochlear implantation.

“The second type of congenital hearing loss is conductive hearing loss. This results from an abnormality in the conductive mechanism, which consists of the ear canal, tympanic membrane [which separates the outer ear from the middle ear] and middle-ear ossicles [bony structures that connect the tympanic membrane to the middle ear]. These patients have a ‘conduction of sound’ problem, which can be corrected by implanting a bone conduction device that sends the sound to a healthy cochlea via transcranial bone transmission of sound.”

Acquired conductive hearing loss arising from chronic middle-ear disease or trauma can’t always be treated with conventional hearing aids. In conditions where the ear canal is prone to discharge after initial surgery it works better to place a bone conduction implant in the skull behind the ear. This eliminates the need for an earpiece inside the ear canal, says Dr Nell.

Acquired sensorineural (nerve) hearing loss is a condition where cochlear function is affected over time (slow onset) or sudden, e.g., a condition called sudden onset sensorineural hearing loss. In these patients the ear drum and canal are normal, but the cochlea is affected. This condition is suitable for a cochlear implant.

Cochlear implant 

The cochlear implant device consists of a receiver that is placed under the skin behind the ear and an electrode array that is placed in the cochlea via the round window. An externally worn microphone and sound processor sends the sound to the implanted device. 

Surgery to place the implant is performed through an incision behind the ear to insert the electrode array. An opening is then drilled through the mastoid bone to expose the round window through which the electrode is inserted. 

Six weeks after the implantation surgery, the implantation is activated for the first time by the audiologist involved. After the implantation, sound perception is initially different to natural sound perception but, with time and input from the audiologist, good speech recognition is achieved. 

Bone conduction hearing implant

A bone conduction device assists patients with conductive hearing loss. This device, attached to the bone behind the ear with titanium screws, sends sound vibrations to the cochlea, bypassing the ear canal and middle ear. Like all the implantation devices discussed, it’s not visible externally, explains Dr Nell. “This operation is not major surgery and is easier and quicker to do than the cochlear implantation, although both implantations are conducted with the patient under general anaesthetic.”

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