Basic knowledge about Cochlear Implant

We sincerely thank the "Deutsche Cochler Implant Gesellschaft" and the editors of "Die Schnecke" for the kind permission to use their text and image material, which we have adapted in parts to the occurrences of Luxembourg. The originals and much more information can be found at schnecke-online.de.


Die Fachzeitschrift der Deutschen Cochlea Implantat Gesellschaft e.V.
Hauptstraße 43
89250 Senden
Tel 07307 / 925 6642
Fax 07307 / 925 7475

01.What is a Cochlear Implant?
The Cochlear Implant (CI) is an inner ear implant that is surgically implanted in the cochlea. It can make deaf people hear. CIs convert sound into electric signals that directly stimulate the auditory nerve in the inner ear. An implant has two components:
• the outside component is the sound processor, that is generally worn behind the ear and, by means of a magnet antenna, transmits digital impulses,
• the inside component, the actual implant, is inserted into the cranial bone close to the ear, has a coil to receive signals and an array of electrodes which are placed into the cochlea.
02.What’s the difference between a CI and a hearing aid?
Hearing aids amplify sound, which is transmitted via the eardrum to the inner ear and the cochlea. These are beneficial with hearing loss, but not with deafness. A CI converts sound into electronic impulses, which are sent directly to the auditory nerve without passing through the ear.
03.Who is a cochlear implant candidate?
A CI is an option for deaf-born children or children and adults who have severe hearing loss and receive limited benefit from hearing aids. Even people who suffer from hearing impairment as a consequence of a disease like for example a sudden hearing loss or an accident that lead to hearing impairment. The prerequisite for a successful implant is a functioning hearing nerve. Whether the auditory nerve is intact can only be determined in an otorhinolaryngologist clinic (ENT-specialists).
04.When should I have a Cochlear Implant inserted?
At the earliest possible stage, as soon as the profound deafness has been reliably detected and cannot be healed any other way. Children born with profound deafness should have a CI implanted within the first years of life. The first implantation is eligible for children beginning at 5 months of age. The ability to hear, speak and receive information develops during the first years of a child. If the capability to hear is impaired during this time of great cognitive development, the brains’ language and speech center is prevented to develop correctly. Even for adults it is important that the period of deafness is as short as possible in order to relearn hearing and understanding.
05.What's important for parents to know?
Among one thousand newborns, one to three babies have a severe hearing disorder. In Luxemburg, the hearing ability of every newborn babies is medically examined (Newborn-Hearing-Screening). Different methods, namely ABR (auditory brainstem response), or OAE (otoacoustic emissions testing) might be used. Both tests only take a few minutes and are completely painless and harmless. The measurements are very sensitive and the results are very likely to indicate an existing hearing impairment. However, there is a risk of "positive wrong" result, which means the examination shows an abnormality, even though the child's hearing is fine. Therefore, every child with a conspicuous screening result should have a medical check-up in a pedaudiological center. Parents should be close to their children during the medical examination.
06.Is the treatment concluded with the surgery?
No. The sense of hearing has to be learned. Every patient hears differently. The brain has to learn to grasp the electronic signals created by the CI and received by the hearing nerve. It's like learning a foreign language. If I do not know the meaning of a word, I only hear sounds, without understanding them. After the surgery, the initial activation is made in a specialized clinic. The objective is to find a comfortable volume that makes the patient perceive as much as possible and identify sounds. Regular fitting sessions are necessary to adjust the CI to the hearing development of the patient. Simultaneously, the patient should go to auditory training. At the beginning this is done in an intensive inpatient or outpatient rehabilitation (Rehab). Subsequently, CI-patients are reliant on lifelong, specialized and individual follow-up care, and above all they need to be willing to learn.
07.Where can I get myself or my child operated?
CI surgeries are not carried-out in Luxemburg. Meanwhile, many clinics in our neighboring countries Germany, France and Belgium offer CI surgery. The experience of the surgeon and the cooperation with experienced therapists are important, which is closely linked to the number of annual surgeries and the technical specialization of the clinic. The insertion of electrodes into the inner ear is not a routine, because every cochlea is different. Not every electrode is suitable for every inner ear. The more experience the surgeons and the clinics have been able to accumulate, the safer the success of the surgical intervention. The surgery can only be successful if the auditory nerve in the inner ear is intact. For this determination, the surgery team should have access to professionals from other medical disciplines. This is most likely in large ENT clinics. Moreover, the treatment is not concluded with the surgery. Post-rehabilitation support is equally important. The hearing consultants and the board members of the "LACI - Lëtzebuerger Associatioun vun de Cochlear Implantéierten" are glad to assist you in finding a clinic with a CI center. An updated overview of clinics and CI centers in Germany can be found on the homepage of the German Cochlear Implant Society (DCIG) (www.dcig.de).
08.How long does the surgery take?
Usually between two and four hours.
09.For how long do I need to stay in hospital?
Usually three to four days.
10.Is the surgical procedure performed under general anesthesia?
11.How risky is such a surgery?
Cochlear implantation is no riskier than any other middle ear surgery under general anesthesia. To minimize the risk, you should only trust a CI-experienced team. The operation should be performed "minimally invasive" in the sense of a "soft surgery"with the least possible damage to tissue and bone. It is also important that any remaining hearing capacity is preserved and that the auditory nerve is not damaged, in terms of future technical and medical advances as well.
12. Can I hear immediately after the surgery?
No, at first the wound must heal. This can take up to four weeks. After that the speech processor will be switched on. It must be fit to the individual hearing of the patient. These settings are reviewed and adjusted regularly. This is made in specialized CI centers. The objective of the adaptation of the speech processor is to give the patient the opportunity to hear and distinguish the complete spectrum of noises, sounds and voices. This can be achieved very quickly, but may as well take months or years. Specialized therapists help during this process. Patience and the willingness to learn are indispensable.
13.If I am deaf or extremely hard of hearing in both ears - should I have two CIs inserted?
Yes, because hearing from both sides is always better than hearing in one ear only. This topic should be discussed with the treating doctor. It is important that both ears are optimally supplied with hearing systems. In some cases, it may be beneficial to use a CI on one earand a hearing aid on the other. Experts call it bimodal hearing. Certainly, hearing on both ears has great benefits (binaural hearing). This makes ambient sounds easier to identify and to locate, furthermore the speech understanding is better. It helps at school, at work and during leisure time. It reduces traffic dangers and facilitates the musical enjoyment.
14.Is CI an option, if only one ear is deaf?
Meanwhile, thanks to technical progress: Yes, it is. People who have normal hearing on one ear and are deaf on the other, report better hearing and understanding since they have a CI in the deaf ear. The tinnitus, which is often present in such cases, is usually meliorated by the CI. This results in better opportunities at work and great gains in quality of life. Only people hearing in both ears can locate the source of a sound.
15.How expensive is a CI and which costs do the health insurances bear?
Currently the insertion of a CI costs about as much as a car of the lower middle class. Moreover, aftercare costs, batteries and spare part costs must be added. Other accessories such as microphones and amplifiers, or broadcasting equipment (FM systems) are often needed to improve understanding in classrooms, lecture halls, offices, or conferences. If the medical conditions are given (indications), the health insurance companies bear these costs completely. However, the treating specialist in Luxembourg has to apply for a treatment abroad at the Luxembourg health insurance. The health insurance company selected by the patient in the respective country will then render the accounts with the Luxemburgish health insurance. Usually, all charges that the foreign health insurances covers are refunded.
16.Do I hear the same thing as a normal hearing person with the CI?
No. Two people never hear exactly the same thing. CI wearers can only hear approximately "normal". The degree of convergence and the time to achieve it entirely depends on the individual patient, the period and cause of deafness, the course of the surgical intervention, the state-of-the-art and the quality of the aftercare. Many CI carriers complain mainly about problems when making a call, in a noisy environment (background noise) or during musical enjoyment. In general: the more modern the technology used and the more qualified the aftercare, the less significant these problems become.
17.Are there different CI systems? Which one should I choose?
Currently, four manufacturers offer cochlear implants, each of them work on the same principle, but differ in terms of details, design and accessories. In most cases, these companies also make other related medical devices: for example hearing aids, bone anchored hearing aids, middle ear implants or brainstem implants. Sometimes different aids can be combined. Which system is best for you should be discussed with your doctor.