Tinnitus: What you need to know

Nov 28, 2022Tinnitus

Tinnitus is often thought of as the ‘ringing in the ears’ that we might have temporarily after going to a loud concert. However, as many as one in 25 people have tinnitus that affects them long-term, impacting their daily lives and often coming hand-in-hand with mental health conditions, such as depression. But it’s not always heard as a ringing, and those who have it may describe it as buzzing, humming or whooshing.

For some people, the sound pulses in time with their heartbeat – this is known as ‘pulsatile tinnitus’. In general, tinnitus is a sound that comes from within; it doesn’t originate from an external source like the radio or washing machine. Most often, it’s a signal that the affected person perceives as a sound, but is generated in the brain. More rarely, it can be a ‘real’ and sometimes detectable sound coming from the body – like muscles or blood vessels – near to the ears. This is known as ‘somatosound’.

What causes it?

Detectable sound, or somatosound, can be related to high blood pressure. But in the majority of tinnitus patients, it is harder to explain what is happening. We know that it is more than likely caused by damage or changes to the ear, or to the auditory cortex, which is the part of the brain that deals with hearing.

Sometimes the damage comes from repeated exposure to loud noise, or simply growing older. One aspect that makes the cause difficult to discern is that people don’t always hear the sound that they associate with tinnitus until after the damage that caused it occurred. Research suggests the signal is initially masked by the brain, but when other triggers, such as stress, come into play, this in-built ‘noise cancellation system’ breaks, and the signal is perpetuated in the brain by changes in the auditory cortex.

Mild cases of tinnitus, such as the after-effects of gong to a loud concert, will often go away after a few days © Getty images

Who gets tinnitus?

There are several groups of people who are more likely to get tinnitus. One is those with hearing loss; by some estimates, 9 out of 10 people who get tinnitus also have some level of hearing loss. Tinnitus is common in musicians, military personnel – army veterans are more than twice as likely as non-veterans to have tinnitus – and, less obviously, pregnant people.

It’s thought that the changes in blood volume and pressure, water retention, and circulating hormones that occur with pregnancy may affect tissues or nerves in the ear, altering the signals that are sent to the brain. There is also evidence from a 2021 study suggesting that COVID-19 can cause tinnitus, but it’s unclear whether the ears or brain are affected directly, or whether the tinnitus is triggered by emotional stress, like during the pandemic.

Will it go away on its own?

Sometimes. Mild cases often clear up within a matter of days – as in the example of going to a loud concert. However, scientific studies are more likely to be focused on people for whom the symptoms have persisted for longer. According to UK researchers who reviewed evidence from studies published between 1992-2016, symptoms tend to improve the most in the first four months after the person initially notices them, with no apparent change after that.

Many people have to learn to live with tinnitus, leading to serious impacts on their quality of life and mental health. Some studies suggest that having tinnitus can make conditions like depression and anxiety worse. It is also very common for people with tinnitus to develop hyperacusis – increased sensitivity to normal noise levels – which causes further stress and anxiety.

How is tinnitus treated?

In most cases, there is no cure. Medication consists of antidepressants and anti-anxiety pills rather than drugs that directly treat tinnitus. Cognitive behavioural therapy can help people reframe negative thoughts and emotions about the sound and improve their wellbeing, while education and counselling provide reassurance that the sound isn’t a symptom of anything sinister.

Some find benefit in sound therapy, which uses white noise, music or sounds played through smartphone apps, to mask tinnitus. For those with hearing loss, masking sounds can be played through hearing aids. Nerve and brain stimulation are potentially exciting new therapies.

A safer option is stimulating branches of the vagus nerve – which extends into the brain’s auditory cortex – at the ear or neck, with studies showing reduced distress and a slightly reduced perceived loudness of the tinnitus. Meanwhile, Australian researchers are working on brain stimulation using electrodes strapped to the outside of patients’ heads, claiming to have temporarily silenced tinnitus in some people for several days.

If you suspect you may have tinnitus, you should book an appointment to see us for a baseline hearing assessment and discussion with one of our audiologists.

Credits: This article was published on BBC Science Focus https://www.sciencefocus.com/the-human-body/