The Vibrant Soundbridge is an implantable hearing aid.
It is implanted under the skin behind the ear and connects to the middle ear where it mechanically vibrates the middle ear structures. The amplified vibrations can be adjusted to optimally compensate for different kinds of hearing losses.
Consisting of two parts, the Vibrant Soundbridge has an external portion and an implanted portion. The external component, the audio processor, is held over the implant by magnetic attraction (similar to a cochlea implant). It can be worn discreetly and comfortably under the hair. The implanted part of the Vibrant Soundbridge is called the VORP (Vibrating Ossicular Prosthesis) and incorporates the Floating Mass Transducer (FMT).
Sounds are detected by the microphone in the audio processor. The audio processor converts the sounds to electrical signals, which are transmitted across the skin to the implanted part of the device. The implant relays the signal from the coil abd demodulator down the conductor link to the Floating Mass Transducer (FMT). The FMT converts the signal into mechanical vibrations that directly vibrate the ossicles, sending the signal to the fluid-filled inner ear (cochlea). This motion creates movement in the fluid of the cochlea, stimulating the hair cells. The hair cells provide stimuli to the auditory nerve, which are then interpreted by the brain as sound.
The VORP is implanted during a surgical procedure. There are two ways to attach the FMT. Firstly for sensorineural loss, the FMT can be attached to the ossicular chain (ear bones) by way of a special clip attached to the incus. When activated, the FMT vibrates in a controlled manner, specific to each patient’s hearing needs, causing the structure of the ear to vibrate (see Diagram 1). The second option, for mixed or conductive hearing loss, is where the FMT is placed so it stimulates the round window to directly drive the inner ear fluids. This second option is particularly suitable to atresia patients who have malformed ossicles (ear bones) (see Diagram 2).
The Vibrant Soundbridge is suitable for conductive, sensioneural or mixed hearing losses, where conventional hearing aids are not appropriate. It directly stimulates only the cochlea on the side with the hearing loss (with no crossover), allowing for localisation and binaural stimulation and not affecting the quality of sound in the hearing ear.
This middle ear implant offers an alternative treatment option for aural atresia cases, and is offered in combination with ear reconstructive surgery overseas. It is anticipated that this combined approach will also be available to Australian families in the future.
The Vibrant Soundbridge is suitable for children, and now has approval in Australia to be implanted in children. The manufacturer recommends implantation for children 3 years of age or older.