Cochlear Implant

A cochlear implant is a surgically implanted electronic device that bypasses damaged cochlear hair cells and delivers electrical stimulation directly to the auditory nerve via an electrode array placed in the cochlea. It is offered to children and adults with severe-to-profound sensorineural hearing loss who derive insufficient benefit from hearing aids. NHS specialist centres at Guy's and St Thomas', Great Ormond Street and South Tees perform cochlear implantation as part of regional implant programmes. The implant consists of an internal receiver-stimulator placed under the scalp behind the ear, an electrode array threaded through the round window or a cochleostomy into the scala tympani, and an external sound processor magnetically coupled to the internal receiver. NHS patient information notes that surgery is performed under general anaesthesia, lasts approximately 1.5-3 hours per side (3-6 hours bilateral), with facial nerve monitoring throughout. Most adults are discharged the same day or after one overnight stay. The external sound processor is activated approximately four weeks after surgery to allow swelling to subside, after which a programmed series of mapping ("switch-on") appointments tunes electrical thresholds and comfort levels. Auditory rehabilitation continues over months to years, and most adult recipients achieve good open-set speech understanding. International patients typically need a return visit at around 4-6 weeks for activation. Sources: NHS Guy's and St Thomas', NHS South Tees, NHS Great Ormond Street, NIH/PMC literature.