| Tom Nebe |
ILLERTISSEN, Germany (dpa) – After 30 years of silence, Dr Roland Zeh could hear again. He had gone deaf at age seven, in 1967, when the technology for a cochlear implant (CI) still lay in the future.
In 1998, he got a CI for one ear.
“A culture shock,” recalled Zeh, now president of the German Cochlear Implant Society. “An extremely stirring experience. Almost a sensory overload.” In 2002 he got a CI in his other ear as well.
A cochlear implant is an electronic device that can provide a sense of sound to people who are severely deaf due to inner-ear damage. It includes a processor worn outside the ear that captures sounds, which are converted into electrical im-pulses and sent, via a transmitting coil, to an electrode array placed in the cochlea (inner ear).
Bypassing the damaged parts of the cochlea, the electrodes directly stimulate the auditory nerve, which sends the impulses to the brain, where they are interpreted as sound.
Zeh couldn’t immediately understand speech after the operation. That is normal. It often takes a lot of time and auditory training.
“I had to relearn to distinguish between diffe-rent sounds first,” he said.
“Some people are better at it, others worse,” noted Claudia Becker, who heads the Department of Sign Language and Audiology Education at Berlin’s Humboldt University. She said progress depended on how well the brain was able to pro-cess the new auditory stimuli.
Zeh estimates that between 30,000 and 40,000 people in Germany currently have a cochlear implant.
A total of 72 cochlear implants were performed last year at a typical treatment centre, Erfurt’s Helios Hospital, according to Dr Dirk Esser, chief physician in the hospital’s Department of Otor-hinolaryngology (ear, nose and throat). The pro-cedure takes about two hours.
Since many severely deaf people can still hear low-frequency sounds, a cochlear implant is often supplemented with a hearing aid.
“The CI makes high-frequency sounds audible, which is important in understanding speech,” Zeh said, while the hearing aid amplifies low-frequency sounds and thereby provides a better overall hearing experience.
It had long been debated whether children who are born deaf (prelingual deafness) should get a CI. “It’s a good alternative but no
guarantee” they’ll learn how to speak, Becker re-marked.
Studies have shown that only about half of these children acquire natural, spoken language, she said, adding it was therefore important that they be taught sign language in case the implant doesn’t work as hoped.