What is Tinnitus?
Tinnitus is a sound in the ears or head which is not from an external source.
There are many types of tinnitus sounds. The most common observed Common are a hiss, whistle, whirr, ring or buzz. Sometimes, people report hearing segments of music. Pitches can be high or low and the level can vary over time.
The mildest severity of tinnitus is extremely common. Lots of people experience occasional sounds in their ears, for example after being in a noisy place such as a concert or loud bar.
There are two main types of tinnitus: subjective and objective tinnitus
- Subjective – This can be heard by the patient only. It’s the most common type of tinnitus.
- Objective – This can be heard by somebody examining the patient and is uncommon. It can be caused by a variety of physical effects such as spasm of the tiny muscles in the inner ear, abnormalities in the blood vessels around the ear, increased blood flow to the ear or anatomical abnormalities of the blood vessels.
What Causes Tinnitus?
Tinnitus causes a change or disruption in the transmission of the signal going from the cochlea to the part of the brain that processes sound, known as the auditory cortex. This causes some of the neurons, or nerve cells, in the auditory cortex to not receive signals like they should.
In some people, these neurons react by developing random ‘chatter’, which becomes synchronised to create the illusion of sound. Over time, this firing pattern is strengthened and the tinnitus can become a constant sound.
The following factors are known to be involved in the development of tinnitus:
- Hearing loss
- Exposure to loud noise
- Injury to the ears or head
- Ear infection
- Disease of the ear e.g. otosclerosis.
- Side effect of medication
- Emotional stress