Tinnitus is a condition where noises are heard in the ears or in the head. Most people will experience some buzzing or ringing in the ears, especially after exposure to loud noise.
What noises do people hear?
The way people perceive tinnitus varies enormously - from just one sound to a mixture of whistling, ringing, buzzing and rushing sounds. The condition is common among deaf and hard of hearing people but it also happens to a small number of hearing people.
What are the noises?
The noises that are heard are not fully understood but are generally considered to be the noises of the internal workings of the ear and the nearby arteries and veins. For people without a hearing loss all that can be said of these noises is that somewhere along the line from the cochlea to the auditory cortex, irregular electrical signals are being generated, producing sounds.
For people with a hearing loss the explanation is a little more involved. The hearing pathway has a complex filtering system that allows you to ‘tune in’ to sounds that are important to you – like an early warning system – and ‘tune out’ sounds that are not important. This system is always working and stops you from being bombarded with sounds. Your brain has a similar system that responds to sounds. Together these systems help to control how you react to sound and set-up a sound threshold.
This threshold stops very quiet sounds being picked up over background noise. When you lose some of your hearing, your brain sets the sound threshold lower to compensate for the hearing loss. By doing so you are able to pick up the internal noise levels of the workings of your own ear.
What causes tinnitus?
Tinnitus is a symptom, not a disease and there can be many different causes. It can be linked to exposure to loud noise, hearing loss, ear or head injuries, some diseases of the ear and some ear infections, or it can be a side effect of some medication. It may be a combination of all or some of these or a person may never have any of these conditions.