Europe: New Hearing Technology In Test Phase

  • By Breffni O'Rourke


Prague, 11 August 1998 (RFE/RL) -- Deafness and partial loss of hearing affect millions of people around the world.

In past centuries there was little which could be done to help those born with hearing defects, whose hearing systems were damaged by disease or declined with age.

Historically seen, plain shouting was the normal way of communicating with the partially deaf, perhaps through a long horn which gathered and concentrated the sound in the ear.

People with impaired hearing long suffered from feelings of social isolation, not least because, being unable to react normally when spoken to, they were often regarded as mentally deficient.

Then, with advances in technology this century, came the electrically-powered hearing aids which are so familiar today. These little machines have done wonders to improve the lives of those with hearing deficiencies. Essentially seen, a hearing aid fulfills the traditional role of the old ear-horn: it gathers acoustic sound from the environment and amplifies it as it comes into the middle ear.

But there are still problems. A conventional hearing aid is indiscriminate in the sound it picks up. Somebody wearing one at a cocktail party for instance will usually be receiving a confusing babble of sound without the differentiation that a normal ear conveys. There is also the question of distortion of sound, and socially speaking, people are still shy about being seen with tell-tale external equipment.

A measure of the comparative dissatisfaction with the devices can be gained from British statistics. The national health service there spends $80 million annually equipping people with hearing aids, but it estimates that some 20 percent of these aids are not being worn by recipients.

However technology moves forward, and there are new ideas in this field as in every other. One California-based company, Symphonix, has been working on a miniaturized electronic technology which is claimed to avoid many of the problems. It's called the "vibrant soundbridge", and is designed to assist people with hearing loss in the high-frequency range.

The soundbridge is divided into two components, one external and one implanted in the skull. The external part is a little more than one centimeter across and can normally be concealed under the hairline. It contains a microphone, a battery and the electronics needed to convert sound into signals, which are sent to the implanted part.

This internal part consists of a receiver, a conductor link and a special gadget called a "floating mass transducer" (FMT). A signal from the external part passes through the receiver to the FMT, which in turn converts the signal to vibrations that move the bones of the middle ear similar to the way that normal sounds move them. Symphonix's Swiss-based European director John de Mora-Mieszkowski, explains:

"The new device, because it works directly on the three little bones in the middle ear, eliminates the problems associated with hearing aids, in that you don't have anything in the ear or the ear canal, you don't get any disturbing acoustic 'feedback' from the microphone, and you don't get the feeling of 'overcrowding', quite the reverse, you get a much more natural sound".

Asked if the prospect of an operation to implant the internal part of the device might deter many potential users, De Mora-Mieszkowski says he does not believe it will. He describes the operation as a standard procedure which takes about an hour, and says the implanted equipment has a 10 to 20 year life span, like a heart pacemaker.

He says that in clinical trials around west Europe, some 100 test patients have reported good results. The soundbridge has now been given CE mark approval, which means it is cleared for use within the European Union countries, and those non-EU countries which observe the same regulatory standard, including Switzerland, Norway and some of the Central and East European applicant countries.

De Mora-Mieszkowski says that the new technology will be formally introduced to medical experts from Central and East Europe at an international scientific congress of ear, nose and throat specialists in Bratislava in October.

The congress, an annual event in the Danube region, will be presided over this year by the Slovak specialist Milan Profant. Experts from the Czech Republic, Hungary, Poland, Romania, Bulgaria and Slovenia will be among those present, as well as from host country Slovakia.