What can help adults with hearing loss or deafness?

Put simply, the possible treatment options depend on which part of the ear is damaged, and how badly:

• If sound waves no longer reach the inner ear properly (or at all), it is called conductive hearing loss. That means that there is a problem in the outer or middle ear. Depending on the cause, sound conduction can be restored or at least improved again – for instance, with surgery or special hearing aids that direct the sound towards the inner ear through vibrations in the skull.
• In the inner ear, the cochlea receives sound waves from sensory cells and changes them into electrical signals. Damage to the inner ear leads to what is known as sensorineural hearing loss. The word "sensorineural" comes from "sensory" (senses) and "neural" (nerves). A typical and common example is age-related hearing loss. Hearing aids that amplify the sound waves can help in people with mild to moderate hearing loss. Cochlear implants (prostheses) are an option for severe inner ear hearing loss or complete deafness. This kind of implant changes sound waves into electrical signals that travel along the auditory (hearing) nerve to the brain.

Some hearing problems are only temporary. The sound may then be muffled by a middle ear infection or a blockage in the ear canal. This type of hearing loss goes away again once the cause has cleared up, perhaps because an inflammation has died down or earwax has been removed from the ear canal.

If there's a problem with sound being passed on in the middle ear – for instance, due to a condition called otosclerosis, where the ossicles (tiny bones in the middle ear) get stuck in place – surgery is an option. Sometimes a small prosthesis is then fitted, to take over the function of one or more of the ossicles. After the operation, the sound waves are generally passed on better to the inner ear again. But a hearing aid is still sometimes needed as well.

Permanent hearing loss and deafness are usually caused by problems in the inner ear. They can't be fixed, but can often be improved with hearing aids or cochlear implants.

Many adults with hearing loss can understand other people better again with the help of a hearing aid. That also improves their quality of life. But hearing aids can only work if the inner ear is still able to pick up some sound waves. If that is no longer the case, a cochlear implant is more likely to help.

In Germany, statutory health insurers usually cover the costs of a hearing aid if it is prescribed by a doctor and 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:

• Behind-the-ear devices: 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.
• In-ear devices: These devices are worn completely in the ear, like an earplug or a wireless in-ear headphone.

• 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. 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 passes them on 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 (or bone conduction) hearing aids pass the sound waves directly on 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. Regular checks and hearing tests are needed afterwards as well.

You have to get used to wearing the hearing aid, and accept that some things might sound different than they did before you had hearing problems. People who have lived with hearing loss for many years are often used to guessing what other people are saying. You have to learn to rely on your hearing again. It can also take a little practice to operate the device and, for instance, learn how to change the batteries or avoid unpleasant interference.

Behind-the-ear and in-ear hearing aids can increase the risk of ear canal inflammations (swimmer's ear). People who receive implanted hearing aids always need to have surgery when they are implanted. This is associated with quite rare risks, including infections, bleeding and nerve injuries. The device might not work properly, but that's rare too.

Hearing aids don't really help in people who are totally deaf. Simply amplifying the sound (making it louder) wouldn't be enough for 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. People with severe hearing loss usually have an implant fitted in each ear.

The treatment is given in specialized ear, nose and throat (ENT) clinics, known as cochlear implant centers. 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 passes them on to the cochlea through a fine electrode wire. Depending on the sounds picked up by the microphone, the signals are passed on to different parts of the cochlea. The auditory 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.

A cochlear implant may be considered if a hearing problem in the inner ear is so severe that sound-amplifying hearing aids would no longer help. The hearing nerve still has to be intact so that the electrical signals can be sent to the brain. Otherwise, a cochlear implant won'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 help people to hear better and try to recognize sounds.

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 (but overall rare) complications mainly include bleeding, wound healing problems and infections. Injuries to nerves or problems with the anesthetic are also possible, but even less likely.

After the operation, the processor has to be adjusted and you start doing hearing and speech therapy. That can take up to a year for adults, and several years for children.

Things will sound different with the cochlear implant than they did when your hearing was still normal. The therapy helps you to get used to this “new hearing” and to learn what spoken words now sound like, for example. You also learn how to deal with the technical side of the cochlear implant, as well as any additional functions it may have. That is often done in the same clinic, but sometimes in a special rehabilitation facility instead. The cochlear implant is still checked regularly afterwards too.