A condition called misophonia—where people adversely react to particular sounds, often with feelings of rage, terror, fear and panic—was first identified 20 years ago, but is only now starting to be better understood, as Dr Karl Kruszelnicki writes.
The human body is incredibly complex. We are still learning about it—in fact we are still discovering new human diseases.
So let me introduce you to what appears to be a disease so new that you won’t find it in your spell-checker, or your favourite dictionary. In fact, this 'disease' is so new it might not even turn out to be a real disease.
It's called 'misophonia'—literally meaning 'hatred of sound'.
Misophonia is a disorder of how your brain processes sounds, so you get extremely powerful negative emotions in response to some everyday sounds.
These trigger sounds are overwhelmingly generated by humans. About 80 per cent of them are related to the mouth, and about 60 per cent have a strong repetitive element. Trigger sounds include eating, chewing, footsteps, breathing, yawning, a cat licking its paws, and even the plosive sound of the letter P, as in 'Peter Piper picked a peck of pickled peppers'.
In people who have misophonia, the response to the trigger sound is a strange and extreme combination of rage, terror, fear, panic and anger. It seems to be related to the flight, fright or freeze response in the sympathetic nervous system, which has evolved to get you ready for dealing with emergencies.
In about 5 per cent of cases, the trigger sound leads to actual physical violence, while in about 25 per cent of cases it results in verbal violence. In most cases, though, the anger gets bottled up.
People with misophonia have insight into their condition. They understand that their aggressive reaction to a trigger sound is both excessive and unreasonable, and that the loss of self-control is unacceptable. So they often try to avoid the trigger sounds by all kinds of workarounds, including wearing noise-reduction headsets, which unfortunately cut out a whole bunch of other useful sounds as well.
Misophonia was first identified in 1997 by the audiologist, Marsha Johnson. She called it '4S' or 'Selective Sound Sensitivity Syndrome'. It was the married researchers, Margaret and Pawel Jastreboff from Emory University who first coined the term 'misophonia' around the year 2000. However, the condition has not been yet accepted into the Psychiatric Bible known as DSM-5, or the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
On average, misophonia appears when you’re about 13, but it can turn over at a fairly wide range of ages. And unfortunately, it gets worse over time—you get sensitive to a wider range of trigger sounds over time.
This condition is quite different from 'hyperacuisis', where an ordinary sound appears to be excessively loud and painful. And also from 'tinnitus', which involves a ringing sound in the ears, but which is actually happening in the brain.
A relatively small study in early 2017 showed that people with misophonia had abnormally high activity in the anterior insular cortex when exposed to their trigger sounds. This part of the brain tells our consciousness what it should pay attention to—it integrates information from the body as well as from external sensory inputs.
The brain centres that process sound also fired up much more strongly in people with misophonia on hearing their trigger sounds. And brain scans also showed a remarkable degree of hyperconnectivity between the auditory systems, and the systems that process emotion.
It’s early days so far—especially for a condition that is not yet even officially recognised—but there are already some treatments that seem to work.
Both cognitive behaviour therapy (CBT) and some brain training techniques appear to have some degree of success. Alcohol seems to make it better, while caffeine can make things worse.
But anything is better than nothing, when an innocent sound can be a trigger for another person's bite.