For conductive or mixed hearing loss:
Middle ear implants (MEI) work by directly vibrating the bones or structure in the middle ear, bypassing the damaged or blocked parts of the outer or middle ear, and getting sound straight to where it’s supposed to go to i.e. to the inner ear (cochlea). The tiny vibrating component of the implant is typically coupled onto the incus (a middle ear bone), though in certain cases it may need to put onto a different structure in the middle ear. This depends on CT scans and/or findings during the operation itself. The surgery to implant a MEI is a very delicate procedure and typically takes longer than a bone conduction hearing implant surgery for this reason.
The implant converts sound into vibrations which are then transmitted to the inner ear (cochlea). This stimulates the auditory nerve and allows the brain to perceive and interpret sound.
Middle ear implants work differently to bone conduction hearing implants, because they stimulate the specific ear that the implant has been surgically placed on – this can potentially help with ability to interpret sound in background noise (especially if the patient has normal hearing, a hearing aid or another MEI on the other side) and with the ability to localise where sound is coming from.
For sensorineural hearing loss:
The MEI works in the same way as described above i.e. the middle ear is directly stimulated via a small vibrating component which sends the sound to the inner ear. A MEI is an option particularly for patients who cannot tolerate or wear conventional hearing aids i.e. normal hearing aids. This may be because the normal hearing aid is causing an allergic reaction or outer ear inflammation; or because the outer ear has not formed properly (i.e. microtia/ atresia – as long as the middle ear is healthy and intact). It is important to note that MEI cannot be surgically implanted in cases of profound sensorineural hearing loss (because the cochlea won’t be able to pick up the sound sufficiently). It is also not suitable for patients who have active middle ear infections.
Ask your audiologist whether you may be suitable for this implant. Please note that assessments for MEI can be long, and may involve several appointments and/or scans which will then be discussed in a multidisciplinary team meeting with the ear-nose-and-throat (ENT) surgeon.