Cochlear Implant: What Is It?

The so-called cochlear implant is a new type of technology that is used by people with hearing problems. In this article we explain exactly how the device works.

The so-called cochlear implant is a new type of technology that is used by people with hearing problems. In this article we explain exactly how the device works.

Since the cochlear implant is a transducer, it converts acoustic signals into electrical signals in order to stimulate the auditory nerve of the respective patient.

The device is relatively new. The first devices that were tested with a certain degree of success in the hearing impaired date from the 1950s. However, technological advances have made their further development possible.

It is important to know that the cochlear implant is not a hearing aid. The former is used through a surgical procedure, while the latter is always outside the body and also functions differently.

The quality of life of the patients who receive the implant improves significantly. Still, the end result will vary as it depends on various factors. In some cases, it may take several years of adjustment for the device to show its maximum benefit.

However, it is positive that the device, once implanted, does not cause any restrictions in the everyday life of the hearing impaired. The vast majority of activities can be performed without any problems.

How is the cochlear implant structured?

The cochlear implant is made up of various components. Here, external and internal components can be distinguished, depending on the final position, i.e. inside or outside the body. External include the following:

• The microphone picks up the noise.

• The processor selects the sounds picked up by the microphone to break them down into useful and useless codes.
• The transmitter coil transports the signals from the processor to the internal components of the implant.

The internal components include:

• The receiving coil is surgically inserted into the mastoid, a part of the skull bone behind the ear. It receives the noises from the transmitter coil in order to transmit them to the electrodes.
• The electrodes are also implanted inside the ear. They directly stimulate the nerve cells so that the respective signal reaches the auditory nerve.

How does it work?

As soon as the microphone picks up external noises, it transmits them to the processor. In this they are processed in order to distinguish which language can be formed from and which cannot. The sounds are then digitized.

This digital sound has properties that differ from the normal sounds that a healthy person without hearing problems can hear. People who use the cochlear implant usually describe the sound as metallic. Therefore, it is difficult to differentiate between different voice colors the first time you use it.

The digitized sound is transmitted from the outer to the inner part of the implant via the connection system. As soon as it reaches the organism, the receiver coil converts the digital codes into an electrical signal so that the inner ear is stimulated by means of the electrodes.

Each electrode corresponds to a specific frequency of the acoustic signal. This is used to generate a specific signal for the auditory nerve by the stimulated electron. The brain then receives this signal via the auditory nerve and generates a hearing sensation.

Who is the cochlear implant suitable for?

The cochlear implant is particularly advantageous in the following cases:

• Severe hearing loss in both ears: This can be assumed if the person concerned does not speak or only utters individual words, has little or no control over his or her voice and can neither articulate nor pronounce the majority of the phonemes correctly.

• Various ineffective hearing aids have already been tried with a simultaneous loss of quality of life.
• Less than 50 percent of the sentences are understood during a hearing test.
• Less than 60 percent of the sentences are understood during a hearing test even though a hearing aid is worn.

The previous examination will be carried out by an ear, nose and throat specialist. This will perform audiometry, tomography and magnetic resonance imaging of the brain and hearing.

Apart from these medical indications, other conditions must also be met for the implant to perform its purpose. Therefore, not only physical, but also psychological factors play a role.

It is important that the hearing impaired person shows their will and is aware of the importance of the implant. The adjustment process that follows can be difficult and requires engaging with it throughout. In addition, the acoustic sound of the device is different from normal.

For children who are to have the implant inserted, it is therefore almost mandatory to take part in subsequent programs that will help them interpret the noises.

Furthermore, persons who undergo an operation must be examined psychologically by specialist staff. This is the only way to determine whether they are suitable for the further procedure.