What is a Cochlear Implant?
21 Jan 2022
A cochlear implant is an electronic device that provides a sense of sound to people who are deaf or hard of hearing. A cochlear implant has two parts, one that is placed surgically under the patient's skin behind the ear with its electrodes in the cochlea, and the second part is the outer part. A cochlear implant helps adults, children, and babies with hearing loss.
Cochlear implants are better than hearing aids for adults and children with profound hearing loss. Cochlear implants bypass the damaged portions of the inner ear and directly stimulate the auditory nerve. The implant generates electric signals sent to the brain through the auditory nerve; the brain recognises these signals as sound, but this will not result in normal hearing. People who undergo cochlear implant surgery take time to learn to interpret the signals from the implant as sound. Within a year or so of receiving the implant, patients are trained enough to understand speech, interpret sound, watch T.V., talk over the phone, have meaningful communication, and identify the source of sound even in busy or noisy environments. These are especially beneficial for children or infants born with hearing impairment or developed very early childhood. The implant surgery is done in early childhood below two years of age.
Cochlear implants are expensive. On average, they can cost anywhere between $30,000 and $50,000 in the United States and about £20,000 to £30,000 in the U.K. In India, the costs are significantly lower. It is cheaper, but a city like Delhi also has experienced surgeons and world-class hospitals. Doctors in Delhi have decades of experience in treating patients worldwide and are trained in various treatments, including cochlear implant surgeries. They specialise in complex treatments like joint replacement (knee/hip), bone marrow transplant, cardiac surgery, renal and liver transplant, cosmetic surgeries, and dental surgeries. Hospitals have provided affordable medical care to Indian and global patients in the city. They have treated hundreds of thousands of medical tourists from all parts of the world, including the U.S., Europe, Central Asia, Africa, and elsewhere.
People travelling to Delhi for cochlear implant surgeries must remember to conduct thorough research on the surgeon, hospitals, or clinics before they travel, set up online consultations, and figure out a plan for follow-up visits. Cochlear implants will require follow-up visits to activate the device and speech and language therapy, especially for children. In the case of infants and children, patients or parents must chalk a plan keeping all of these things in mind.
What are the components of a Cochlear Implant?
A cochlear implant contains the following parts:
● Microphone: The microphone picks up sound or sound waves from the outside environment.
● Speech Processor: It selects the sound picked by the microphone and converts it into digital signals.
● Transmitter and receiver: These receive digital signals from the processor, convert them into electric impulses, and forward them.
● Electrode array: This is a group of electrodes that receives the impulses from the receiver and sends them to the auditory or cochlear nerve. It stimulates the cochlear nerve, resulting in the sense of hearing.
How does a Cochlear Implant Device Work?
Cochlear implants mimic the functioning of a healthy ear. They are meant for people with damaged sensory hair cells inside the inner ear. These are better than hearing aid devices as those only amplify the sound. A cochlear implant bypasses the part of the ear that isn't functional, stimulates the auditory nerve and sends signals to the brain, which helps a person have a sense of hearing. Cochlear implants require training and follow-up speech therapy over a few years for patients to get used to them and develop language and communication skills. The implants are also adjusted and fine-tuned by audiologists over a period of time, depending on the patient's needs.
Infants born with hearing impairment and who have never heard sounds before forming new brain pathways can make sense of sounds they receive through the implant. With speech therapy, these infants can understand and interpret these sounds, understand speech, and learn to communicate and develop language skills. Speech-language pathologists (SLP) or auditory-verbal therapists (AVT) can help children develop listening and speaking skills over time. Researchers have documented a significant improvement in language skills and comprehension of children in the first 2-3 years of the surgery.
Candidacy Of Cochlear Implant Surgery
Adults over 18 years of age who have severe to profound sensorineural hearing loss are ideal candidates for cochlear implant surgery. Children with severe to profound sensorineural hearing loss in both ears, who have limited benefit from hearing aids, are ideal candidates.
The ideal way to determine your candidacy for a cochlear implant is to schedule an appointment with an otologist or an Ear, Nose, and Throat (ENT) doctor. The doctor will examine you and ask you for a hearing test. The audiological tests determine the type and the amount of hearing loss and if you cannot understand speech properly. Based on the results, the doctor will recommend more tests that determine your candidacy for an implant.
A person usually undergoes speech, auditory, general communication, balance, language skills assessment, a medical evaluation, and computed tomography (C.T. scan) or magnetic resonance imaging (MRI test) to determine their candidacy.
Hearing aids help people with mild to moderately severe hearing loss hear better by amplifying sound. These are small, wearable, battery-operated devices that consist of a microphone, an amplifier, and a speaker. The microphone receives the sounds from the environment and converts them into sounds waves. The amplifier magnifies sounds, and the speaker sends that sound into the person's ear, helping them hear.
They are different from cochlear implants. Unlike cochlear implants, which stimulate the auditory nerve creating a sense of hearing, hearing aids only amplify sound. Hearing aids are best suited for people with mild or moderate hearing loss. Still, cochlear implants are helpful in cases where patients have profound sensorineural hearing loss, which is related to the inner ear or the auditory nerve. The cochlear device helps you hear by creating an electrical stimulation, unlike a hearing aid. People with moderate to profound hearing loss are those who can understand about 50% or less of spoken words.
Cochlear implants are better suited for infants under 18-months old and children with profound hearing loss. These can help infants and children learn better and understand speech better. In terms of wearability, the inner component of cochlear implants is permanently attached, whereas hearing aids can be removed when not needed. Cochlear implants also require a surgical procedure to be placed in a person's ear, which is not the case with hearing aids. It takes a person about a year to get used to the device, whereas, in the case of hearing aids, people adapt to it in about a week or two.
Cochlear implants are meant for both adults and children. Children as young as six to 18 months can benefit from these implants. It helps children and adults hear speech without visual clues; it allows them to recognise everyday sounds, identify the source of these sounds, listen to music, watch T.V., and talk over the phone. Cochlear implants also help people hear easily in a noisy environment like a crowded room or the middle of a traffic jam.
Cochlear implants are beneficial for people with cochlear or sensorineural perceptive hearing loss. This means that their inner ear or the hair cells are damaged or insufficient. The cochlear implant helps people bypass the broken inner ear, stimulate the auditory nerve directly and send signals to the brain, allowing a person to hear.
Cochlear implants are remarkably suited for children, especially for prelingually deaf children or those born deaf or lost their hearing in early childhood. If a child gets a cochlear implant early in life, at around 12–18 months, it gives them a great chance to learn in school and develop communication and language skills. However, parents should remember that these children require speech therapy after receiving an implant. It will eventually help them develop language, verbal, and communication skills.
Older adults with profound hearing loss also benefit from cochlear implants greatly. It helps them remain independent and continue to have social interactions.
Cochlear implants are helpful for people with both single-sided or bilateral (in both ears) hearing loss. It helps them identify the source of the sound and understand speech in different environments. People with bilateral hearing loss can have their implants placed in one or two sessions.
A cochlear implant is not recommended to people if they have hearing aids that are helping them understand speech sufficiently, if their auditory nerve is damaged, or if the cochlea is not the primary cause of their hearing loss. People who are not fit for surgery may also not be recommended for a cochlear implant.
One Cochlear Implant or Two?
This is an essential concern for people with profound hearing loss in both ears. People who use one cochlear implant can understand speech well in quiet places but may have trouble in more noisy environments. It may become more challenging for them to understand if there is too much background noise. It can be challenging to determine where the sound is coming from.
In children with bilateral implants, it is seen that they can acquire language capabilities efficiently and faster compared to children with only one implant.
If you are someone with one implant and considering a second one, you can visit an ENT doctor who can help you determine if you are a candidate for a second implant based on your tests.
Things need to be taken care of before Cochlear Implant Surgery
For the surgery to go smoothly, there is a list of things that everyone should take care of before, especially in the case of children and infants. The first thing is to get the doctor to address all your general surgery-related questions like what time the patient should stop eating the night before, when you should arrive at the hospital, etc. The second set of questions that need to be clarified before surgery is related to the implant itself. Like: what kind of transplant is the patient receiving, whether their head will be shaved, if there are complications patients or their family should know about, will it be painful, how long is the recovery time and the hospital stay etc. All of these will help you be better prepared, especially if a child is undergoing surgery.
In the case of children, please consult your doctor about preparing them mentally and physically for surgery. There are toys, games, and books available for children undergoing cochlear implant surgery, which can help make the child understand. Meeting with other children and families who have undergone a similar experience can be constructive in preparing yourself and your child. The child will also have to be up to date on their vaccines and undergo a physical exam to ensure that they are healthy for surgery.
In the case of an adult, you must check with your doctor whether you should continue to take existing medications if any, or whether you have any pre-existing conditions that the doctor needs to be aware of. It would be best to be mindful of when to resume these medicines after surgery, especially in outpatient procedures.
It is also essential to know that your device will be activated in a few days post-surgery, and it may need more visits for device mapping and speech therapy over a year or two. Patients may also be asked to do follow-up visits for speech and hearing tests; therefore, it is vital to plan these accordingly if you travel to another city for your surgery.
The procedure of Cochlear Implant Surgery
Results of Cochlear Implant Surgery
Cochlear implants enable deaf and hard of hearing people to have a sensation of hearing. This may be different from normal hearing, but it helps people communicate efficiently. Cochlear implants are highly beneficial in children who were either born with profound sensorineural hearing loss or lost it early in life. These help them in speech and language development and improve their communication ability.
An audiologist turns on the cochlear device. Earlier it was done about 3-4 weeks post-surgery, but now we do it around ten days post-surgery. And it is then mapped, adjusted and fine-tuned over time according to the patient's needs. The patient is also taught how to use it and clean it etc. Children who have undergone cochlear implant surgery undergo listening therapy or auditory rehabilitation and speech and language therapy. These will help children identify sounds, understand language, and make associations between sounds and meanings. Children have to undergo these sessions for about a year or as required.
Recovery Timelines After Cochlear Implant Surgery
What is the Cost Of Cochlear Implant Surgery in India?
The cost of cochlear treatment in India depends on a variety of factors. These include:
● Consultation fee for surgeon/audiologists etc
● Surgeon fee
● Cost of tests to determine the candidacy of the patient
● Type of cochlear implants
● Type of hospital/clinic patients pick
● Cost of post-implant mapping and speech therapy.
● Cochlear Implant Doctor in Delhi
● Dr Satinder Singh is a consultant, Cochlear Implant Services, Department of ENT at the prestigious Sir Ganga Ram Hospital, New Delhi. Dr Singh is an ENT specialist with vast clinical experience treating ear, nose, and throat disorders. Dr Singh completed his MBBS at NRS Medical College, Kolkata, and has a post-graduate diploma in Otorhinolaryngology from Dayanand Medical College, Ludhiana. He got his DNB from Sir Ganga Ram Hospital, New Delhi, and has done a visiting fellowship focusing on laryngology at Emory University Hospital, Atlanta in the U.S.
● Dr Singh has years of experience in treating patients with hearing problems. His areas of interest are otology and laryngology. And he is a specialist in Implant Otology and Laryngology. He is a member of the Association Of Otolaryngologists of India, Delhi State. He had been a research guide in a thesis involving cochlear implants and has many publications in the field. His papers have been published in journals like the International Journal of Pediatric Otorhinolaryngology, Cochlear Implants International, and the British Journal of Medicine & Medical Research. He is also an associate professor at the Ganga Ram Institute of Post Graduate Medical Education & Research.