Implantable Hearing Aids

For patients with moderate to severe sensorineural hearing loss a new implantable device became available.The Vibrant P (programmable) and HF (high frequency) Soundbridges (Symphonix)work by increasing the amplitude of natural ossicular vibration. They achieve this through a floating mass transducer attached to the long process of the incus (f. The transducer, a hermetically sealed titanium bobbin wrapped in gold wire, contains a magnet (the floating mass) that moves back and forth according to the frequency and amplitude of the sound signal. It is driven by an electronic processor unit, which is connected to it by a fine wire. The processor unit modulates an electrical signal delivered by a receiver implanted in the skull just behind the ear. The external component of the system is held on the side of the patient's head by a magnet and concealed behind the hairline. It contains a microphone, battery, and the electronics to convert sound energy into a signal that can be transmitted to the internal receiver. Because this device directly drives the ossicular chain, auditory feedback is eliminated. Furthermore, the ear canal is not occluded by a mould.