Cochlear Implants in Children

A cochlear implant is a surgically placed electronic device that turns sound into electrical signals and delivers them directly to the hearing nerve, bypassing a cochlea that no longer works. Cochlear implants in children with severe to profound hearing loss give the brain access to sound early enough to build spoken language, provided they are placed young and followed by two to three years of structured rehabilitation.

Dr. Dilpreet Bajwa, Sr. Consultant, ENT, ENT Surgery, Artemis Hospitals, Gurugram, India, has run a cochlear implant practice for more than ten years. Her central argument is that the operation alone does not deliver the outcome. What decides whether a deaf child ends up talking, attending a mainstream school and leading an ordinary life is how early the hearing loss is found, how quickly the child reaches an implant team, and how consistently parents, therapists and teachers work with the child afterwards.

This guide sets out that pathway from first suspicion to the classroom. Two companion articles go deeper. One covers how hearing loss in children is detected, from the 1-3-6 newborn screening rule to developmental red flags. The other covers cochlear implant candidacy, timing, surgery and rehabilitation, including what older children and adults can expect.

Why childhood hearing loss is called a silent disability

Hearing loss is common at birth. Dr. Bajwa cites an expected rate of 1 to 3 children with hearing loss in every 1,000 born. With about 60,000 to 65,000 children born in India every day, she pointed out, even the lower rate means at least 60 newborns with hearing loss every single day, and most of them are not diagnosed in time. She expects the picture to be similar across Africa.

The problem is that a hearing loss cannot be seen. Parents commonly assume that a quiet toddler is simply a late talker, and the loss often goes unnoticed until the child is 2 or 3 years old, sometimes as late as 5. Children with a moderate loss may develop some speech, but it is unclear, which can further delay recognition. By the time the family seeks help, much of the critical period for language development has passed.

That is why the goal of treatment, in Dr. Bajwa's framing, is not hearing for its own sake. It is adequate hearing that produces language, clear speech and normal social interaction.

How a cochlear implant works

A cochlear implant has two parts.

• The internal device is placed during surgery. It consists of a receiver that sits under the skin behind the ear and an electrode array, a thin lead carrying a row of electrical contacts, that is inserted into the cochlea, the spiral-shaped organ of hearing in the inner ear.
• The external component is worn behind the ear. It carries a microphone, a sound processor and a transmitter.

The microphone collects sound, the processor converts it into a coded electronic signal, and the transmitter passes that signal across the skin to the internal receiver. Magnets in both parts hold the external transmitter in place over the receiver. The receiver sends the signal down the electrode array, which stimulates the acoustic (cochlear) nerve directly. In normal hearing, sound vibrates the eardrum and the tiny bones of the middle ear, which set the fluid in the cochlea moving and stimulate frequency-specific hair cells. The implant takes over the job of those damaged hair cells.

An implant is reserved for severe to profound hearing loss. Dr. Bajwa noted exceptions, such as a steeply sloping loss with good low-frequency hearing, where an implant may be considered even when the overall loss is moderate. In children, at least a severe or profound loss is required.

Candidacy and age at implantation, in brief

Children should be implanted as early as possible, because the young brain adapts to sound most readily. Candidacy is a clinical judgement, not a single number on an audiogram. Infants of 3 or 6 months with profound hearing loss are first fitted with hearing aids to see how much development they achieve. A child older than 3 years with severe to profound loss gains nothing from a prolonged hearing aid trial, and Dr. Bajwa counsels the family directly towards an implant. Every candidate has a CT scan and an MRI to confirm that the inner ear and the cochlear nerve can support an implant.

The urgency comes from neuroplasticity, the brain's capacity to reshape itself in response to input. That capacity is greatest up to about 3 years of age and remains substantial until about 5. A child who receives hearing by 3 accepts the implant readily and develops language well. A child implanted at 5 also adapts, but speech clarity does not match that of a child implanted at 1 or 2. Dr. Bajwa's team aims to implant at about 1 year, and some centres implant from 9 months.

The same principle shapes expectations for older patients. An adult who heard normally, developed language and then lost hearing does extremely well with an implant. A person born deaf and implanted at 20 or 40 will gain sound awareness but is unlikely to develop clear spoken language. The detailed criteria and the age-by-age outcomes are covered in the article on cochlear implant candidacy and timing.

Cochlear implant surgery and switch-on in brief

The operation is performed through an incision behind the ear. The surgeon opens the mastoid bone, reaches the inner ear and inserts the electrode array through the round window, a membrane-covered opening into the cochlea. An X-ray on the operating table confirms that the array sits correctly. Dr. Bajwa describes it as a safe operation, safe enough for 1-year-old children, while the family is told about the known risks. Children are vaccinated against the bacteria that cause meningitis before surgery.

About a week later comes the switch-on, when the external component is fitted and the child first hears through the implant. Hearing is not yet understanding: the brain must learn that every sound is different and that sounds carry meaning. Depending on the age at implantation, this adaptation takes 3 to 6 months, and full rehabilitation to normal speech takes 2 to 3 years.

Who is on a cochlear implant team

Dr. Bajwa is emphatic that working with children who have hearing loss is never one person's job. A functioning programme needs:

• an ENT surgeon, who assesses, operates and manages ear disease;
• a paediatrician;
• an audiologist, who tests hearing and programs the implant;
• a rehabilitation therapist;
• sometimes a psychologist;
• the parents, and later the child's teachers.

Parents carry much of the load. The implant must be worn every waking hour, and a child whose parents are busy on their phones and rarely talk to them will not develop speech, whatever the quality of the device. Because the implant is an electronic device, parents also need to recognise when it needs troubleshooting. Once the child joins a mainstream school, teachers, assistive technology and peer support take on part of the work.

How long a cochlear implant lasts

The internal device of a cochlear implant is designed to last a lifetime. Surgery is meant to be a one-time event, and the implant is replaced only if it fails or is damaged, which happens in a small minority of users over the years. The external processor is a different matter: it lasts at least 5 to 7 years, and manufacturers bring out new technology on roughly that cycle, so most users upgrade.

Manufacturers design the internal device to remain compatible as external technology advances. Dr. Bajwa noted that a person implanted in 1984 still uses the same internal device more than four decades later, having upgraded only the external part.

Follow-up and remote programming for international patients

For families who travel for surgery, the obvious concern is what happens after they return home, where trained audiologists may be scarce. Most current devices have built-in Bluetooth, and programming is now available online. The audiologist and the family connect through the manufacturer's app on a laptop or phone, and the device is programmed wirelessly, in much the same way as a video call. The family does not need to travel back for each adjustment.

Cochlear implant cost: price range and device tiers

Dr. Bajwa put the rough cost of cochlear implant surgery including the device at about 14,000 US dollars at the lower end, rising to about 36,000 US dollars for high-end implants. Cochlear implants are not covered by insurance for Indian families, and the device is expensive. Indian patients can draw on corporate social responsibility (CSR) funds and government programmes; Dr. Bajwa noted that nothing equivalent is currently available for international patients.

Three major companies make cochlear implants, each with several models. Dr. Bajwa's team sets out the advantages and disadvantages of each and lets the parents choose. Implants have been in use for about 40 years, and in her experience every device works, the inexpensive ones as well as the expensive ones. The price differences come from three features:

1. MRI compatibility. MRI scanner strength is measured in tesla. The more expensive devices have magnets compatible with 3 Tesla MRI scanners; the less expensive ones are compatible only with 1.5 Tesla.
2. Automatic programming. Higher-end processors scan the listening environment every 3 seconds and switch settings on their own, for example when the user walks from a quiet room onto a noisy road.
3. Built-in Bluetooth, which connects the processor directly to a phone, tablet or computer.

Dr. Bajwa's advice to parents is that a basic device is a sound choice: the external component will be upgraded within about 7 years anyway, small children do not need sophisticated features, and features such as Bluetooth only start to matter once a child reaches school age. Current package estimates appear on the cochlear implant surgery cost page.

Childhood hearing loss in Africa: scale and prevention

The World Health Organization's Regional Office for Africa expects about 54 million people on the continent to be living with hearing loss by 2030. Many countries have few ENT surgeons, audiologists and speech and language pathologists, and newborn screening is not routine. Dr. Bajwa argues that doctors have a duty to press their governments for systems that both identify children with hearing loss and fund their rehabilitation, whether with simple hearing aids or therapy.

The most encouraging figure is that about 60% of childhood hearing loss is preventable, through measures such as vaccination and adequate access to antibiotics.

Cochlear implants in children: the principles to take away

Dr. Bajwa's closing message is simple: act early, because the brain is developing, and stimulate it while it is at its peak. Hearing aids and cochlear implants both give access to sound, and intensive rehabilitation turns that access into language. Given the right facilities and support, children with hearing loss are no less capable than children with normal hearing.

The questions doctors raised during the session, including adult candidacy, chronic illness, device lifespan, remote programming and cost, are answered in full in the Live Discussion. Related ENT material is collected on the ENT specialty page.