The ability to listen to sound is indeed a blessing. Taking care of the ear is more than just making sure it is clean visibly but also to take care of the inside of the ear. There are many things that could go wrong and affect a person’s ability to hear well. You should ask a doctor if you start to feel there are changes to your hearing abilities. Unfortunately, in some cases, people might need extra help from devices such as cochlear implants to improve their ear function. The question is, can a person hear after cochlear implant?
Before answering that, you might want to understand a bit more on how a normal person hears sound. When there is a sound, the sound is transferred into the ear canal. This will cause the eardrum to move or vibrate. The vibration will then be transferred to the ossicles or known as the tiny bones in the middle ear. This ossicle amplifies the sound and sends them to cochlea in the inner ear. The cochlea is a snail-shaped structure filled with fluid. The movement of fluid makes the hair cells in the cochlea transfer the sound information in electrical signals to the brain. The brain will then translate this information into recognizable and meaningful sound.
Thus, when the cochlea is unable to function correctly, the transferring of information which is in sound to the brain is disturbed. There are many reasons why a cochlea becomes damaged or dysfunctional such as from ageing, exposure to loud noise, injury, certain medications or diseases and even an inherited condition. Since there are many causes that can lead to a damaged cochlea, it is best for patients who have started to have hearing loss to get checked by a doctor as soon as possible. For babies with cochlear problems, they may show signs of no reaction towards loud sounds.
To fix the cochlear problem, one of the ways is to perform a cochlear implant. A cochlear implant is a small complex electronic device that is given to a person with profound deaf or severely hard-of-hearing. The implant consists of an external portion that is placed under the skin through surgery. An implant consist of few part including:
- a microphone that receives sound from the environment
- a speech processor which selects and arrange sounds that has been picked up
- a transmitter and receiver/stimulator that receive signals from the speech processor and convert them into electric impulses
- electrode array of which the electrode collects the electric impulses before signalling the stimulus to different part of the auditory (hearing) nerve where it will be interpreted by brain as sound
For cochlear implant, there are several selection criteria that need to be considered before a person can receive it. Below are among the criteria:
- Candidate’s age- Children that have hearing problems before speaking have to be below 4 years old. Even so, a patient that is already 4 years old can be considered for a cochlear implant based on certain conditions. There is no maximum age limit for adult patients and children who already speak before having hearing problems.
- Hearing impairment- Profound hearing loss in both ears.
- Hearing aid trial- Patients have used hearing aid consistently for some time but gain no benefits from it.
- Patient health level- Patients are proved to not have other health problems that can prevent from undergoing surgery and does not have absence of the auditory nerve.
- Involvement of patients and caregivers- Patients are focused and cooperative during evaluation and therapy sessions. Patients and caregivers are committed to treatment sessions.
Now, can a person hear after a cochlear implant provided through surgery and therapy? It is important to note that an implant does not restore normal hearing. On the other hand, it gives a useful representation of sound in the environment and aids in understanding speech. Cochlear implant itself is not a magic tool that can restore hearing in patients. It will take time for the patient to be able to reap its benefit. Since not everyone is able to perform at the same level with the device, interpreting the sound and to learn sound created by an implant will take immense time and practice. This is why selection criteria is important to ensure patients who receive it are at least at higher chance for success in utilising cochlear implant.
There is much research that is ongoing to help enhance the benefits of cochlear implant. This includes using a shortened electrode array that can help preserve certain frequencies of sound while improving hearing loss. It is important to understand there is still room for improvement for cochlear implants and researchers are looking for ways to make it easier for patients to use it. Patients who are looking forward to the implant should discuss thoroughly with their healthcare provider before agreeing on the procedure as the process of improving hearing loss is indeed a long way.
