Why noise irritates some people more than others: It’s all in the brain

While noise sensitivity is often overlooked by health professionals, it can have long-lasting effects on the mental and physical wellbeing of humans.

Studies suggest that between 20% to 40% of people are more sensitive to everyday sounds than the average, leading to a higher levels of stress, annoyance, or anxiety.

Research shows that noise sensitivity has biological roots rather than being just a personality trait.

In recent years, neuroscientists have discovered that the brains of noise-sensitive people process sound differently, which might make them more reactive to noise.

Daniel Shepherd, a neuroscientist at Auckland University of Technology in New Zealand stated, “It’s been one of those what we might call a wastepaper basket sort of issues… that just gets pushed away by health professionals.”

Only in recent years “have people actually really started to say, right, this is at an experiential level really impacting patients”, he added. “We really need to actually start getting a handle on this.”

Although noise sensitivity is not a formal medical diagnosis, but it can be identified via questionnaires like the 21-question Weinstein’s noise sensitivity scale, which assesses reactions to various everyday sounds.

It differs from similarly related conditions such as misophonia, which involves a strong negative reaction to specific sounds like chewing or tapping, or hyperacusis, where sounds are perceived as louder or more painful than they really are.

In contrast, noise sensitivity includes a heightened reactivity to a wide range of sounds, irrespective of its volume.

Physiologically, the noise can trigger a “fight-or-flight” response in sensitive individuals, and can raise their heart rate and blood pressure. In some cases. sleep can also be affected.

A 2021 study of 500 adults in China found that while noise itself did not drastically change sleep quality, noise-sensitive participants reported feeling less rested and more fatigued the day after.

There are connections to long-term health as well. Research led by Professor Stephen Stansfeld at Queen Mary University of London found that noise-sensitive men in the Welsh town of Caerphilly were more likely to face anxiety and depression when exposed to road traffic noise.

A 2023 French study of residents near airports reported that those who were highly disturbed by aircraft noise were more likely to rate their general health as poor.

Brain studies provide more insights.

According to Shepherd’s research, noise-sensitive individuals have increased brain activity in response to both threatening and non-threatening sounds. This may be linked to differences in the medial geniculate nucleus, which is a part of the brain that filters sound information, which appears less efficient at filtering out irrelevant noise.

The reduced filtering is also observed during sleep, where fewer brain “spindles” happen, making it harder to adapt to background noise.

The causes of noise sensitivity are still being explored. While twin studies from Finland suggest there might be a genetic component, environmental factors might also play a role.

The condition is more common in individuals with anxiety, schizophrenia, autism, or a history of brain injury, and it often lasts a lifetime.

Addressing noise at its source looks like the most effective long-term solution.

Urban planning measures like sound-dampening road surfaces, noise barriers, reduced speed limits, and quiet zones have been put in place in some European cities.

However, the change is slow, and many people cope with noise sensitivity symptoms by themselves by using ear protection, or noise-cancelling devices.

In certain cases, treating underlying issues like anxiety with medication or cognitive behavioural therapy can help lessen the stress.

Music therapy that uses soft, calming tunes, such as Renaissance or Baroque chamber music, may also be useful. Art therapy can offer a different way to relax and manage emotions.

While noise is an unavoidable part of modern life, understanding its effects on sensitive people could lead to better public health measures and, ultimately, quieter and healthier living environments.