What can help children with hearing loss or deafness?

Hearing problems in children are often just temporary. The sound is then perhaps muffled by a blockage in the ear canal, or due to a build-up of fluid in the middle ear (glue ear).

This type of hearing loss disappears again once the cause has cleared up. For example, when the earwax or the foreign body has been correctly removed from the ear canal, or when the middle ear is well aired again and the fluid has drained off.

Birth defects or changes to the outer or middle ear after birth can permanently impair hearing. Some of those problems can be cured or eased with surgery. Sometimes, a cochlear implant is fitted in the middle ear, to take over the function of one of the ossicles (three tiny bones that pass sound on to the cochlea). People can then hear better again after the operation, but a hearing aid is sometimes still needed.

If permanent hearing loss or deafness in children is caused by problems in the inner ear, though, it can't be cured. But it can often be improved with hearing aids or with cochlear implants.

A hearing aid can help if hearing loss doesn't get better on its own or can't be treated. But only if the inner ear is still able to pick up some sound waves.

The costs of a hearing aid prescribed by a doctor are usually covered by statutory health insurers if hearing tests have shown that you have hearing loss. If both ears are affected, it makes sense to have two hearing aids, and the costs of both are covered.

Hearing aids pick up the incoming sound waves with a microphone, amplify them (make them louder), and direct them into the inner ear. They can then be heard better there. Hearing aids are powered by a small battery.

There are different kinds of hearing aids. Which one is best will depend on the type of hearing loss and how old the child is.

• Behind-the-ear hearing aids: These devices are placed over the ear with a hook and worn behind the ear. They forward the amplified sound into the ear canal through a thin tube.

• Bone conduction hearing aids: These devices change sound into mechanical waves and pass them on to the skull. Because the inner ear is embedded in the skull, it can pick up the waves through the bone. These devices are an option if there's a sound conduction problem in the middle ear, perhaps due to a birth defect that can only be operated on when the child is older. They can be worn on the arm of a pair of glasses or on a headband, or glued behind the ear.
• Implanted hearing aids: Partially implanted devices are the most commonly available type at the moment. One part is worn behind the ear, and the other part is implanted into the tissue. The outer part picks up the sound waves, processes them, and sends them to the implanted part. Depending on the system, it then passes them on to the skull, the ossicles (tiny bones in the middle ear) or directly into the inner ear. Devices known as bone-anchored hearing aids transfer the sound waves directly to the skull bone and the inner ear. This is done through a screw that is implanted in the skull.

A new hearing aid first has to be individually adjusted. You need to be patient, which can be particularly difficult for young children. Regular checks and hearing tests are needed afterwards as well, and sometimes special hearing and speech therapy too.

Children have to get used to wearing one or two hearing aids and practice using the device, especially at the beginning. If the child is young, their parents have to take care of the latter and, for instance, learn how to change the batteries.

Behind-the-ear hearing aids can increase the risk of ear canal inflammations (swimmer's ear). Surgery is always needed for implanted hearing aids. This is associated with quite rare risks, including infections, bleeding and nerve injuries, and sometimes the device might not work properly. Then further treatment or another operation may be needed.

It doesn't make much sense for a child to use hearing aids if they are completely deaf. Simply amplifying the sound (making it louder) wouldn't allow the inner ear to pick it up properly.

But a “hearing prosthesis” can be considered. This device converts sound waves into electrical signals. That normally happens in the inner ear, in the sensory cells of the cochlea. For this reason, the prosthesis is called a cochlear implant. In deaf children, an implant is usually fitted in each ear.

The treatment is given in specialized ear, nose and throat (ENT) clinics, known as cochlear implant centers, with an associated phoniatrics and pediatric audiology department. Various experts are involved in the planning, treatment and follow-up care, including ENT specialists and engineers who are specialized in cochlear implants.

A part of the device known as the “speech processor” picks up the sound waves with a microphone and converts them into digital information. The round transmitter coil then sends that information across the skin to the implanted receiver.

The receiver converts the information into electrical signals and sends them to the cochlea through a fine electrode wire. The electrode wire passes the signals on to different parts of the cochlea, depending on the sounds picked up by the microphone. The auditory (hearing) nerve carries these signals to the brain, where they are processed.

The surgery is carried out under general anesthesia, which puts you in a sleep-like state where you don't feel any pain. The receiver is implanted and the electrode wire is fed into the cochlea. The speech processor and transmitter are worn on the scalp behind the ear.

First, a thorough assessment is done to see whether a cochlear implant is the right option for the child. Tests are done to find out how much the child can still hear. If their hearing is so bad that hearing aids wouldn't help enough, a cochlear implant might help. But doctors first have to find out whether the problem really is in the cochlea. Otherwise, a cochlear implant wouldn't help.

If the hearing nerve is damaged, an auditory brainstem implant could be used instead of a cochlear implant. This device stimulates certain areas of the brain. That can also help people to hear and try to recognize sounds. But this procedure is only very rarely recommended for children.

If hearing problems are present at birth or from a young age, they are generally treated as soon as possible to prevent problems with speech and language development. The children then usually get implants within the first two years of their life. The operation is possible from the age of six months.

Implants can still be fitted in older children who have had severe or total hearing loss since birth. But older children are less likely to be able to process and understand the new signals they hear, and less likely to learn to speak as a result. It is thought that by the age of about three, children’s brains have already got used to not hearing, making it more difficult for them to “re-learn.” Because children develop at different rates, it's not exactly clear when it might be too late for a cochlear implant.

But it does still make sense to use cochlear implants in older children who were able to hear and speak before losing their hearing.

The operation is performed by specialist ENT doctors and is considered to be low-risk. Sometimes, a second operation is needed because the device doesn't work properly, but that's rare. Like with any operation, the possible complications mainly include bleeding, injury to the nerves, problems with the anesthetic, wound healing problems, and infections.

Once the surgical wound has healed, the cochlear implant has to be fine-tuned at a number of appointments to ensure that the child gets the most out of it. That is often done in the same clinic, but sometimes in a special rehabilitation facility instead. Even if cochlear implants usually last for several decades, they are checked regularly and might be replaced sooner. Special hearing therapy and speech therapy is also started after the operation.

Children who have cochlear implants, and also children who have worn hearing aids from a young age, hear things differently to people who can hear well. In hearing and speech therapy, a specialized speech therapist first allows the child to get used to all the different sounds. The child then gradually learns to recognize different sounds and make the sounds themselves. They also learn how to use the cochlear implants.

This therapy usually continues over many years. The goal is to understand speech well, and also to be able to speak well. Children’s brains can be influenced when still developing. Because of this, children who get cochlear implants at a young age can generally learn to communicate with other people in the same way as children without hearing problems do – often without doing a lot of therapy. If that's the case, it's quite possible that they will be able to go to a regular school. Some children who have cochlear implants can even learn to play a musical instrument.

If a child still needs extra support, it is usually a good idea for them to go to a special school for hearing impaired children. Some children also learn sign language or lip-reading. Then they can communicate with other deaf children or their deaf parents.