hear better Finally back
"I beg your pardon? I can not understand you. Can you please speak louder, "Who understands his opponent only with difficulty, gets not only quickly into social isolation, but also in dangerous situations - such as on the road. A hearing aid is therefore for those affected - in Europe which is almost half over 65 years - indispensable. For heavily hearing impaired but conventional, worn behind the ear devices are reaching their limits. Those affected only helps an implant that reinforces the classic systems and noted the sound more through a better sound quality. The problem: These middle ear implants can be used only in several hours of operations. The complex procedures are risky and expensive - they are therefore rarely performed. However, the patient may hope: Currently, scientists at a new hearing device that can be implanted much easier and therefore is affordable for many.
The new solution consists of three parts: an external housing with microphone and battery, a wireless, optical signal and power transmission between the outer and middle ear and a sound transducer - core and speaker of the implant. Researchers at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart develop the approximately 1,2 millimeters large, round transducer. Partners in the project, which promotes the Federal Ministry of Education and Research, the University ENT Clinic Tübingen, the Scientific Medical Institute NMI at the University of Tübingen and the auric hearing GmbH. "Our goal is to combine the better sound quality implantable hearing aids with a greatly simplified operation," says Dominik Kaltenbach, an engineer at the IPA. "In order to use our system must be only solved and opened the eardrum side. This is possible in an outpatient procedure. "
Microactuator sits between middle and inner ear
The transducer, which is implemented as a piezoelectric microactuator, then plugs directly into the connection between middle and inner ear - "round window" called - place. He transmits the auditory signal in the form of enhanced mechanical vibrations to the inner ear, thus increasing the hearing. "The transducer works on the principle of bending actuator" explains Kaltenbacherstrasse. "The cake-like arranged bending elements made of a composite layer of piezoceramic and silicon. When a voltage is applied, the elements turn up and produce a mechanical vibration. This carries over to the membrane of the round window and the inner ear and thereby stimulating the auditory nerve to ".
The effect: Although the oculus implant is no bigger than a pinhead, it achieved a computational power of up to 120 decibels. This corresponds to the volume of a jackhammer. "Especially on high notes this great power is required for a very good speech understanding, because in particular the ups take severe hearing impairments no longer true," the researchers from the IPA says.
Currently, a first functional samples in the laboratory, the experts test positive. "The individual components of the hearing aid are developed, the next step must be optimized and assembled," says Kaltenbach. The demands on the implant are high: The material must be encapsulated biocompatible and its long-term stability, finally hearing aid implants must hold at least ten years. In June this year the optimized components are present, the test of the entire system is scheduled for 2014.
Source: Stuttgart [Fraunhofer Institute for Manufacturing Engineering and Automation IPA]
