Cochlear implants (CI) are designed for individuals with severe to profound sensorineural hearing loss. These individuals receive little or no benefit from hearing aids. CIs bypass the non-functioning part of the cochlea in order to deliver electrical signals directly to the auditory nerve. They can be used effectively by both prelingually and postlingually deafened children and adults.
A cochlear implant consists of two parts, an external and an internal component.
A. INTERNAL
a. Implant
The implant consists of a housing, which contains the electronics, and the electrode array as well as the receiving antenna and a magnet that holds the coil in place behind the ear.
B. EXTERNAL
a. Audio processor
The audio processor is worn behind the ear and consists of a control unit, a battery pack, and a coil that transmits information through the skin to the implant.
Cochlear implants convert everyday sounds into coded electrical impulses. These electrical pulses stimulate the auditory (hearing) nerve so that the brain can interpret these signals as sound. As the brain receives sound information very quickly, sounds are heard as they occur.
Cochlear implant systems can offer a wide range of benefits including hearing speech, environmental sounds and music. Results reported with today’s cochlear implants consistently indicate speech understanding for the majority of implanted patients. Benefit from a cochlear implant is most readily measured within the scientific community by the percentage of speech a cochlear implant user can understand in a laboratory setting without lip-reading. Although open set speech understanding is a very important measure of hearing ability, it is by no means the only benefit cochlear implant users report. The perception of environmental sounds, such as doorbells, alarm signals, etc. can make a substantial difference in the life of a person who is severely hard of hearing.
EAS is a hearing implant solution designed for people with partial deafness. These individuals have residual hearing in the low frequencies but have a profound hearing loss in the high frequencies. For people with partial deafnesss, hearing aids often provide unsatisfactory results in understanding speech or listening to complex sounds such as music. Traditional cochlear implant systems are also not ideal because they do not allow users to benefit from their natural low frequency hearing abilities.Combined Electric Acoustic Stimulation, or EAS, is the concept of using acoustic amplification and cochlear implant technology together in the same ear. With EAS, the inner ear is provided with acoustic and electric stimuli and is able to process both high and low frequency information simultaneously.
EAS consists of two parts, an external and an internal component.
A. INTERNAL
a. Implant
The implant consists of a housing, which contains the electronics, and the electrode array as well as the receiving antenna and a magnet that holds the coil in place behind the ear.
B. EXTERNAL
a. Audio processor
The Audio processors features a digital acoustic unit for amplification that enhances a person’s natural low-frequency hearing and is worn behind the ear. For higher frequency sounds, the cochlear implant function automatically takes over. The intelligent integration of both modalities results in a synergistic effect for speech and sound perception offering an optimal solution for individuals with partial deafness.
EAS is the combination of two technologies, each responsible for a specific frequency range. Here is how it works:A cochlear implant converts everyday sounds into coded electrical pulses. These pulses stimulate the auditory nerve. The brain interprets these signals as sound.
Middle ear implants are used to treat people with sensorineural, conductive and mixed hearing losses. These implants are an implantable alternative to hearing aids. Unlike hearing aids that make sounds louder, a middle ear implant takes sound and converts it into mechanical vibrations. A middle ear implant is directly attached to a structure in the middle ear. It causes this structure to vibrate in much the same way that sound (acoustic vibrations) travelling down the ear and through the eardrum causes middle ear structures to vibrate. These acoustic vibrations are amplified and can be adjusted to optimally compensate different kinds of hearing losses. The most successful middle ear implant on the market is the Vibrant Soundbridge. It is a partially implantable hearing system that consists of two parts, an external and an internal component.
A. INTERNAL
a. Implant
The internal, implanted part of the Vibrant Soundbridge is called the Vibrating Ossicular Prosthesis (VORP) and consists of the internal coil, magnet, conductor link and the Floating Mass Transducer (FMT).
B. EXTERNAL
a. Audio processor
The external part is called the Audio Processor, which is held onto the head and underneath the hair with a magnet. It contains the microphone, the battery and electronics to convert sound in the environment into a signal that is transferred to the implanted internal part.
The signal from the Audio Processor is transferred across the skin to the internal coil, which relays this signal down the conductor link to the FMT. When activated, the FMT vibrates in a controlled manner, specific to each patient’s hearing needs, causing the structure of the ear to vibrate.
VIBROPLASTY
This surgical treatment of hearing loss via vibratory stimulation in the middle ear by using a middle ear implant is defined as Vibroplasty. It is applied in different types of hearing losses for patients who only achieve limited benefit from conventional hearing aids. Vibroplasty is also often performed in patients with insufficient benefit after conventional middle ear surgeries. In Vibroplasty treatments, the FMT may be placed onto different structures in the middle ear, depending on the individual condition and anatomy.
With the Incus Vibroplasty, the FMT is attached to the incus, one of the three small bones of the middle ear. The FMT converts the signal into vibrations that directly drive and move the ossicles, similar to the way normal sound moves them via the ear canal. These vibrations then are interpreted by the brain as sound.
A bone conduction implant is suitable for individuals affected by conductive hearing loss, mixed hearing loss or single-sided deafness. Because sound is transmitted to the inner ear via bone conduction, problems in the outer or middle ear are bypassed.
The Bonebridge is the world’s first active bone conduction implant on the market. It is a semi-implantable hearing implant system in which the implant is positioned completely under the intact skin. The implant receives signals from an externally worn audio processor.
A. INTERNAL
a. Implant
The Bone Conduction Implant (BCI) is positioned completely under the intact skin and contains a magnet that holds the audio processor in place above the implant by means of magnetic attraction.
B. EXTERNAL
a. Audio processor
The audio processor is held in position on the head by magnetic attraction and can be worn underneath the hair. It contains the battery and the microphones and is equipped with a fully digital signal processor.
Bone conduction hearing implant systems may be recommended when the natural transmission of sound to the inner ear is impeded. In bone conduction hearing systems, the cranial bones are stimulated by mechanical vibrations. These vibrations are transmitted directly to the inner ear, where they are processed like normal sound.