There are several types of technology that assist some deaf people to hear more than they do without the technology. There are two main types of technology that are worn. They are:
- hearing aids – these are worn on the outside of the ear
- cochlear implants – these have a component that is surgically implanted as well as a component that sits on the outside of the ear
Whilst these two things can look similar, they actually work in very different ways.
Cochlear implants or CIs
The first step with a CI is for the deaf person to undergo a delicate operation to insert 22 electrodes into the cochlea or inner ear. This is where the auditory nerve is in the body. At the same time, a magnet and a receiver/stimulator are also placed against the skull bone, just under the skin.
Once healing is complete, an external part of the CI which has a sound processor is worn on the ear and a transmitter runs from this and is attached to the receiver using the magnet.
This device works very differently to hearing aids as it transmits sound directly to the 22 electrodes that sit on the auditory nerve. Then, as is the case with people who have hearing, this sound stimulation is carried to the brain via neural pathways in order for the brain to interpret the sound and the individual to hear it.
It is important to understand that whilst a CI does provide sound stimulation directly to the brain, it does not provide normal hearing. Often, media portrayal of the CI is inaccurate, so it is common for many people to think that a CI makes a deaf person hearing. This is not the case. It provides sound stimulation that the user needs to learn to understand. There are varying degrees of success for users of CI; results are very individual and a number of factors come into play.
Originally, people were allowed to only have one ear implanted; however, in recent times, it has become more common for people to have both ears implanted with cochlear implants. However, these are still done one at a time.
To hear a simulation of sound through a cochlear implant, click here
For more information on hearing aids, click here