It’s not yet known exactly what causes tinnitus, but it can be linked to different things. In most cases, it’s a symptom of a problem within the hearing system.

Most cases of tinnitus are linked to hearing loss caused by damage to the inner ear. This type of hearing loss is called sensorineural. Another common cause is exposure to loud noise. Less commonly, tinnitus is linked to hearing loss caused by a blockage or ear condition that affects the outer or middle ear and stops sound waves from passing into the inner ear. This type of hearing loss is called conductive.

Ear problems and conditions that can cause tinnitus include:

• Ménière’s disease
• Glue ear
• Otosclerosis
• A build-up of ear wax
• A perforated (torn) eardrum.

Sometimes, but uncommonly, tinnitus can be linked to:

• Ear infections.
• Ear, head or neck injuries.
• Emotional stress.
• Certain medications, called ototoxic drugs, that are used to treat serious illnesses.
• Neurological disorders including acoustic neuroma, which is a non-cancerous growth that affects the hearing nerve.
• Metabolic disorders including hypothyroidism, hyperthyroidism and diabetes.

However, for many people with tinnitus, there is no recognisable link.

What’s the link between tinnitus and hearing loss?

When we hear, sound waves travel through the ear into the cochlea, our hearing organ in the inner ear. The cochlea is lined with thousands of tiny sound-sensing cells called hair cells. These hair cells change the sound waves into electrical signals. The hearing nerve then sends these electrical signals to the hearing part of the brain, which analyses them and recognises them as sound.

When part of the ear or hearing nerve becomes damaged or doesn’t work properly, this reduces the number of electrical signals usually sent to the brain. This results in a temporary or permanent hearing loss.

Research has shown that fewer electrical signals can make the neurons (nerve cells in the brain) more sensitive, because they are searching for signals that aren’t being received from the ear, leading to hyperactivity. It’s believed that this hyperactivity makes the brain more aware of the electrical ‘noise’ from the neurons, which is heard as tinnitus.

What’s more, if you have hearing loss, you may be more aware of tinnitus. This is because you won’t hear as many environmental sounds that could otherwise help to mask it. In this case, hearing aids may help with both hearing loss and tinnitus.

Two-thirds of people with tinnitus have hearing loss. But it’s important to remember that a third of people with tinnitus have normal hearing, and many people with hearing loss don’t have tinnitus.

How does loud noise cause tinnitus?

Exposure to loud noise can damage the hair cells in the cochlea, leading to hearing loss and tinnitus. Many people have had dulled hearing and an unwanted ringing sound in their ears after a night out in a noisy club or bar. This is thought to be the result of the hair cells becoming ‘exhausted’. If you’ve experienced this, don’t ignore it. Although your hearing may recover within a few hours, it’s a sign that if you continue to be exposed to high levels of noise, your hearing could become permanently damaged.

Four million young people in the UK are at risk of hearing damage because of exposure to loud music in bars, clubs and gigs, and from listening to music too loudly through their headphones or earphones.

Noise-related hearing loss and tinnitus are completely avoidable if you take simple steps, like using hearing protection. For more information on tinnitus, visit the RNID website by clicking here.