Help is available for people with all types of hearing loss. Treatment depends on both the cause and severity of the deafness.
Sensorineural hearing loss is incurable. When the hair cells in the cochlea are damaged, they cannot be repaired. However, various treatments and strategies can help improve quality of life.
Hearing aids
These are wearable devices that assist hearing.
There are several types of hearing aid. They come in a range of sizes, circuitries, and levels of power. Hearing aids do not cure deafness but amplify the sound that enters the ear so that the listener can hear more clearly.
Hearing aids consist of a battery, loudspeaker, amplifier, and microphone. Today, they are very small, discreet, and can fit inside the ear. Many modern versions can distinguish background noise from foreground sounds, such as speech.
A hearing aid is not suitable for a person with profound deafness.
The audiologist takes an impression of the ear to make sure the device fits well. It will be adjusted to suit auditory requirements.
Examples of hearing aids include:
Behind-the-ear (BTE) hearing aids: These consist of a dome called an earmold and a case, with a connection linking one to the other. The case sits behind the outer ear, with the connection to the dome coming down the front of the ear. The sound from the device is either electrically or acoustically routed to the ear.
BTE hearing aids tend to last longer than other devices, as the electrical components are located outside the ear, meaning that there is less moisture and earwax damage These devices are more popular with children who need a sturdy and easy-to-use device.
In-the-canal (ITC) hearing aids: These fill the outer part of the ear canal and can be seen. Soft ear inserts, usually made of silicone, are used to position the loudspeaker inside the ear. These devices fit most patients straight away and have better sound quality.
Completely in the canal (CIC) hearing aids: These are tiny, discreet devices but not recommended for people with severe hearing loss.
Bone conduction hearing aids: These assist people with conductive hearing loss, as well as those unable to wear conventional type hearing aids. The vibrating part of the device is held against the mastoid with a headband. The vibrations go through the mastoid bone, to the cochlea. These devices can be painful or uncomfortable if worn for too long.
Cochlear implants
If the eardrum and middle ear are functioning correctly, a person may benefit from a cochlear implant.
This thin electrode is inserted into the cochlea. It stimulates electricity through a tiny microprocessor placed under the skin behind the ear.
A cochlear implant is inserted to help patients whose hearing impairment is caused by hair cell damage in the cochlea. The implants usually improve speech comprehension. The latest cochlear implants have new technology that helps patients enjoy music, understand speech better even with background noise, and use their processors while they are swimming.
According to the National Institutes of Health (NIH), there were about 58,000 adults and 38,000 children with cochlear implants in the U.S. as of 2012. The World Health Organization (WHO) says approximately 219,000 people globally use one, most of them in industrial countries.
On the outside, a cochlear implant consists of:
- A microphone: This gathers sound from the environment.
- A speech processor: This prioritizes the sounds that matter more to the patient, such as speech. The electrical sound signals are split into channels and sent through a very thin wire to the transmitter.
- A transmitter: This is a coil secured with a magnet. It is located behind the outer ear and transmits the processed sound signals to the internally implanted device.
On the inside:
- A surgeon secures a receiver and stimulator in the bone beneath the skin. The signals are converted into electrical impulses and sent through internal wires to the electrodes.
- Up to 22 electrodes are wound through the cochlea. The impulses are sent to the nerves in the lower passages of the cochlea and then directly to the brain. The number of electrodes depends on manufacturers of the implant.
Children will usually have cochlear implants in both ears, while adults tend to have just one.