Why Chewing Really Is One Of Life's Most Annoying Sounds

It's a sound that can promote a "disgust" reaction. Here's what that means.
AleksandarGeorgiev via Getty Images

The sound of someone chewing has been voted the UK’s most annoying noise. That’s according to a study, which found the second and third most annoying noises were construction work and alarms. (Too right, we need a lie in).

Women are, in general, more irritated by these sounds than men, the research by Curry’s PC World found. But why is it that chewing gets on our nerves so much? After all, we all need to eat – so, we all must chew, too.

Trevor Cox, professor of acoustic engineering, says it’s because chewing is a sound that can provoke a “disgust” reaction. This means it’s not the actual chewing noise that drives people’s annoyance, he says, but “the association with something unpleasant”.

So, in this case, masticating a load of food and saliva in your mouth. Pretty rank.

“We learn to keep away from things like other peoples’ bodily fluids that might cause disease,” he explains. “When I ran a study into the worst sound in the world, where people listened and scored sounds for unpleasantness, the top one was someone vomiting. It isn’t characteristics of the noise that are driving the response, it is the association with something unpleasant.”

In Cox’s own study, the sound of someone eating only came in at 24th. After vomiting, the worst sounds were microphone feedback, the noise of many babies crying at the same time, and scraping/squeaking.

The professor noted that with chewing, the reaction to the sound might relate to how the person perceives the quality of the food, too. “Companies go to a lot of effort to create the right sound when you chew something,” he adds, “e.g. a crisp needs to make a short sharp sound when chewed.”

Cox’s study was across the general population, but he says there are a few people who have an extreme response to such sounds – a condition called misophonia.

“Whether this extreme emotional response is a disgust reaction, or something more to do with anger or annoyance is currently a topic of debate among scientists,” he explains. “Often it is about particular individuals making a particular sound that triggers the response.”

Misophonia describes the unreasonable emotions that come about when some of us hear noises produced around us. While it has been recognised as a condition since 2000, there has been limited research into the cause.

In 2017, researchers at Newcastle University found evidence of changes to the brain’s frontal lobe that could account for the emotional responses that certain sounds triggered in those with misophonia. Brain imaging revealed people with the condition have an abnormality in the emotional control mechanism, which causes their brains to go into overdrive when they hear the trigger sounds.

Dr Sukhbinder Kumar from the Institute of Neuroscience at Newcastle University said at the time: “This study demonstrates the critical brain changes as further evidence to convince a sceptical medical community that this is a genuine disorder.”

Research in 2020 found chewing sounds are less likely to be annoying if they come from an animal, rather than a person – but more is needed to understand why this might be. In the meantime, whether chewing sounds make you angry – or just plain irritated – it might be time to invest in some earplugs.

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