Inner ear prosthesis Listen again after decades

After decades of deafness, inner ear implants allow many a first hearing

07/01/2015

Hearing loss is associated with significant impairments in everyday life and with conventional hearing aids, which are based on an amplification of the sound pulses, this can only be remedied limited. An alternative is so-called cochlear implants (CI), which stimulate the neurones of the cochlea directly. With their help, pigeons can hear again.

For many deaf people, ear-noises have been heard again for decades, thanks to inner-ear implants. Among them is Roland Zeh, Chief Physician of the HTS Department (Hearing Disorders, Tinnitus, Dizziness and Cochlear Implants) at the Median Kaiserberg-Klinik Bad Nauheim and President of the German Cochlear Implant Society (DCIG). At the age of seven, today's head physician suffered a complete loss of hearing in 1967, according to the news portal „World Online“. The hearing aids available at that time could not help him and the physician lived in deafness for 30 years before being implanted in the inner ear in 1998, the first prosthesis.

Electrodes stimulate the auditory nerve
The inserted cochlear implant consists of a microphone and a speech processor, which are attached to the outside and transmit the recorded sounds by induction as impulses to an implanted receiver. This sends the pulses to electrodes in the cochlea, which stimulate the auditory nerve. Thus, those affected take noises without the so-called hair cells are activated. The DCIG president is from „World Online“ quoted as saying that the first perception after surgery, „a very impressive experience, almost a sensory overload, but in a positive sense“ has been. Hardly surprising, if someone perceives noises again for the first time in over 30 years, that this is a veritable cultural shock.

Learn to differentiate the sounds z
Like most patients, the DCIG president needed some time after surgery before he could properly classify the CI's impulses. „I had to learn again to differentiate different sounds“, cited „World Online“ the chief physician. With the help of a special listening training, those affected learn to understand speech and even make phone calls after some time is quite possible. „Some do better, others worse“, explains Prof. Claudia Becker, Head of Sign Language and Audio Pedagogy at the Institute for Rehabilitation Sciences of the Humboldt University Berlin in the article by „World Online“. Already „After a short time of getting used to the CI sounded very pleasant and natural“, The news portal continues to quote head physician Roland Zeh. In the year 2002 Zeh had an implant inserted in the second ear because of the success.

Up to 40,000 people in Germany with a cochlear implant
According to estimates by the DCIG President, today between 30,000 and 40,000 people with cochlear implants live in Germany. Professor Dirk Esser, chief physician of the Department of Otolaryngology at Helios-Klinikum in Erfurt added „World Online“, that in Erfurt alone last year 72 such interventions were made. In an approximately two-hour operation, an access is created in the cochlea to place there the electrode carrier. Immediately below the skin, the doctors insert the receiver coil into the patient, which is connected to the electrode carriers. The costs are given by the experts with 20,000 euros for the implant plus surgery costs as well as costs for the subsequent auditory training and rehabilitation. A reimbursement by the health insurances take place when conventional hearing aids can no longer achieve an understanding of the spoken language.

Combination of conventional hearing aids with the CI
A combination of CI with hearing aids is also possible, according to the experts, for example, if hearing impaired can only perceive the low tones. Through the hearing aid, the low tones are amplified and „The CI then makes audible the high notes that are important for speech understanding“, reports Roland Zeh opposite „World Online“. With complete deafness, however, the conventional hearing aid can not develop any additional benefit.

Use of CI in children
To what extent the inner ear implants are also recommended for deaf-born children was loud „World Online“ controversial for a long time. Prof. Claudia Becker comes to the conclusion that the CI „a good alternative“ but do not provide security. Previous studies have shown that about half of the children develop natural sound acquisition through the CI. The other´Half show despite the CI significant development delays or impaired phonetic acquisition. Therefore, it is important to teach the deaf children sign language anyway, explains Becker. In this way, the children can resort to these if the implant does not develop the desired effect.

Parallel learning of the sign language
Chief physician Roland Zeh explains in the article by „World Online“, that „Children are not deprived of the opportunity to listen“ should. With the help of the inner ear implant, many of them are able to attend a normal school and later have more options for choosing a career, the DCIG president continued. A parallel learning of the sign language is nevertheless necessary. Furthermore, deaf children are faced with the question of the earliest age at which a CI should be used. In the professional world this remains controversial until today, so Prof. Claudia Becker. Whether a similar operation should take place before the second year of life is therefore unclear.

CI not comparable to a healthy ear
Professor Dirk Esser, however, concludes that - depending on the time of diagnosis - a CI should be used even before the first year of life. He considers that the intervention should, if possible, always take place before the language acquisition age. Although the inner ear implants allow a certain auditory impression, but with a healthy ear, this is by no means comparable, reports Roland Zeh. „We are miles away from that“, the chief physician will continue from „World Online“ cited. For example, noise such as traffic noise or other conversations in the same room would make it harder for the CI wearers to hear because the implant „In contrast to the ear, it is difficult to control which sounds it wants to hear, "says the news portal Professor Claudia Becker, adding that the CI can not help all people, as at least the auditory nerve has to be in tact, for example in the womb properly trained, CI can not be used. (fp)