Hearing loss may be broadly classified based on the location of the disorder. The main mechanism may be a problem with the conduction of the sound through the external and middle ear (conductive hearing loss), a disorder of the cochlea and the auditory nerve in the inner ear (sensorineural hearing loss). A mixed hearing loss involves elements of both conductive and sensorineural hearing loss.
A Cochlear Implant is indicated in severe cases of hearing loss of the sensorineural type, when there is dysfunction of the hair cells of the cochlea or the auditory nerve. In these cases, conventional hearing aids may not provide enough sound for adequate development of speech and oral communication.
Cochlear implants have two main parts: an external processor and an internal, implanted, receiver-stimulator. The external part captures sound with microphones, transforms the signal into electric impulses that are transmitted magnetically to the internal receiver. The signal is then delivered directly to the auditory nerve through an electrode placed inside the cochlea.
Three brands of cochlear implants are approved by the U.S. Food and Drug Administration (FDA), and the Cochlear Implant Program at Texas Children’s Hospital provides surgical implantation and post-operative support for all three manufacturers: Advanced Bionics, Cochlear and MED-EL.
As soon as one or both ears qualify, with hearing loss in the moderate to profound range. The decision to proceed with implantation is highly individualized, but, in general terms, early intervention leads to the best possible outcomes. Children who are born with severe hearing loss, or pre-lingual deafness, achieve the best results when cochlear implants are placed around 9 months of age or even earlier. Patients who develop severe hearing loss later in childhood (post-lingual deafness) do the best when they receive implants shortly after hearing becomes worse.
Contact the Cochlear Implant Program Coordinator, Karoline Sellers, BSN, RN via phone at (832)822-3508 or e-mail: cochlearimplants@texaschildrens.org