What is tinnitus?
Tinnitus is an awareness of sound in the ears or head which is not from an external source.
There are many different types of tinnitus sounds. Common descriptions are that it is a hiss, whistle, whirr, ring or buzz. Occasionally, it can be segments of music. The pitch can be high or low and the level can vary over time.
In its mildest form, tinnitus is extremely common and many people experience occasional sounds in their ears, for example after being in a noisy place such as a concert or loud pub. .
There are two main types: subjective and objective tinnitus.
Subjective – This can be heard by the patient only. It is by far 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?
Whatever the trigger for tinnitus, it causes a change to the transmission of the signal going from the cochlea (the hearing organ, or the inner ear) to the part of the brain where sound is processed, known as the auditory cortex. This means that some of the neurons, or nerve cells, in the auditory cortex do not receive signals as they used to. In some people, these neurons react by developing spontaneous ‘chatter’, which becomes synchronised to create the illusion of sound. This is called neural synchronisation. 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:
1. Hearing loss
Tinnitus often occurs along with some degree of hearing loss. But around one in every three people with tinnitus don’t have any obvious problem with their ears or hearing.
2. Exposure to loud noise
Noise is one of the most common causes of hearing loss. A single shot from a large caliber firearm, experienced at close range, may permanently damage your hearing in an instant. Repeated exposures to loud machinery may, over an extended period of time, present serious risks to human hearing.
3. Injury to the ears or head
For more than one in ten suffering chronic tinnitus the problem stems from a neck or head injury.
4. Ear infection
Otitis media is an infection of the middle ear that causes inflammation (redness and swelling) and a build-up of fluid behind the eardrum.
5. Disease of the ear e.g. otosclerosis.
Otosclerosis is a condition in which there’s abnormal bone growth inside the ear. It’s a fairly common cause of hearing loss in young adults.
6. Side effect of medication
Certain medications, such as some chemotherapy medicines, antibiotics, diuretics, non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin (this is more likely to occur at very high doses) can cause tinnitus. Tinnitus is cited as a potential side effect for about 200 prescription and non-prescription drugs.
7. Emotional stress
How you manage your tinnitus may have a connection with the level of stress you are under. If you have a high level of stress there is a greater chance that you will be troubled by your tinnitus.