Firstly, a definition. What is a cochlear implant? An implant is a device etc (read from overhead)……….. What an implant does is: for an adult or child who has heard before, an implant will restore a level of hearing sensation. for a child who has never heard before, an implant will give the potential for hearing. With a child, to maximize this potential for hearing that the implant gives,it is critical that the child undergo listening training to learn to listen with the implant. So an implant is not a miracle sure but it gives hearing potential. This potential the implant provides is significant eg many adults can learn to use the telephone when using the implant and for children, if children are implanted young enough, they can in most cases learn to listen and speak and go through mainstream school
This slide shows the same view of an ear as the previous slide but with a CI in situ Here you can see the implant with electrode array inserted into the cochlea and the electronics package here embedded into the bone behind the ear.. This is the speech processor and headset with microphone. The sound is picked up by the microphone, sent to the speech processor where the important parts of the speech signal are picked out and coded. This code plus power from an external battery is sent to the transmitting coil over the implant. The information is then transmitted across the skin to the implant and decoded. This information is then sent to the electrodes in the form of tiny electrical pulses which directly stimulate the hearing nerve, bypassing the damaged parts of the ear. The nerve then transmits the signal up to the brain where we hear the sound. USE DEMO PRODUCT HERE
This shows a close up of the electrode array in the cochlea. Each dark band is an electrode and you can see how the tiny electrical pulses will stimulate the nerve here
Multiple channel ci were first implanted in children in Melbourne in 1985- 10 year old. Since that time over 10,00 children have been implanted with Nucleus CI and the age of implantation has dropped rapidly As reseach,clinical results on children showed better results when they receive their implant at an early age (during the critical phase of language development) and given our knowledge of language development, physiological studies of the effects of sensory deprivation and the effects of age of hearing aid fitting on outcomes for hearing impaired children.
5 This shows an xray of the electrode array in the cochlea. We have 22 active electrodes in the array which extend around one and a half turns of the cochlea as you can see here. As you probably know the cochlea is organized so that we hear different frequencies in different parts of the cochlea. We hear high sounds here and low sounds here. Because there are 22 electrodes in the electrode array the implant recipient can hear the different frequencies in speech because a high sound will stimulate an electrode in this region and a low sound will stimulate an electrode in this region
This shows the programming equipment and the specialized software used to Map the speech processor.
2-3 weeks following surgery the recipient returns to the clinic for the first fitting of the external companents the term MAPping/programming the procedure required for fine tuning the device to suit each individual’s needs requires specialised software and programming interface systems Is the process of measuring and controlling the amount of electrical current delivered to the cochlea. To provide the patient with comfortable and useful hearing sensations . Theaudiologist sets the speech procesor to the appropriate levels of stimulation for each electrode. The average number of postoperative visits is higher in paediatric than in adult programmes. Device fitting requires at least 2 clinicians. Duration of habilitation is higher.
Listening training is critical Without this the potential of the implant will never be reached
These are the core CI Team members. Viktorija will go into more detail about each member’s role
Cochlear Implants - An introduction R.Ranjith Audiologist Madras ENT Research Foundation Chennai
A cochlear implant is a hearing prosthesis designed to restore or provide a level of auditory sensation to adults and children who have a severe to profound bilateral sensori-neural hearing impairment and who get limited benefit from hearing aids