Author: Ralph

Have you ever felt you could focus better and enter your flow state when working in a cafe? You may have noticed that it might be the background noise in the cafe that helped you stay focused. But have you also felt stressed by a loud background noise, like the drilling sound from a construction site nearby? Today, we will explore the impact of noise – especially those we are exposed to in urban areas – on our cognitive health!

What Are Noise Levels?

Noise levels are measured by decibels (dB). According to the US Centers for Disease, Control and Prevention (CDC), the US Environmental Protection Agency (EPA), and the World Health Organization (WHO) recommend maintaining a noise level below 70 dB over 24 hours to prevent noise-induced hearing loss. Listening to loud music, going to concerts, or hearing sirens are some of the risky activities that could lead to hearing loss.

Just to get a sense of varying levels of dB, here are some examples. Your typical breathing sound is approximately 10 dB, a soft whisper is about 30 dB, and normal conversations have a sound level of 60 dB.

According to the CDC, at sound levels between 70 and 85 dB, you may feel annoyed, and above 85 dB, you may experience hearing loss after a prolonged exposure.

How Does Background Noise Affect Us?

It appears that depending on the noise level, we are affected differently. It appears that the quality of studies investigating the relationship between the exposure to a range of noise levels and cognitive function level generally has low quality. A 2022 systematic review study found that most of the studies on this topic were low-quality studies.

Having that said, there are some studies that indicate cognitive decline with exposure to the high noise level. A 2020 study has shown that an average increase of 10 dB increases the likelihood of cognitive decline and dementia.

In contrast, a 2022 experimental study showed at noise level less than 45 dB helped individuals to focus on their work. While a noise level of around 65 dB also helped with focus, it also increased stress.

A 2021 neuroimaging study using electroencephalography (EEG) explains that background noise affects stress, attention and mental load. Another 2019 EEG study showed that verbal/auditory attention decreases significantly when exposed to the noise levels above 90 dB. A 2013 study showed that children exposed to background noises may face challenges with learning, especially recalling verbal recalls.

Exposure to noise can increase stress hormone level, which may have negative consequences to cognitive health, too. Misophonia is a condition in which a person has increased irritability once hearing sounds like a chewing sound, is an example where noise can increase the stress level. Chronic stress can lead to a cognitive health decline.

What Can We Do About Background Noise?

Now that we have learned how exposure to noise affects our cognitive health, we will explore ways to reduce the noise level in our environment. The US CDC has a few recommendations:

1. Use earplugs or earmuffs: earplugs have many benefits when sleeping. There are different types that you can choose to fit your needs. There are proper steps to using earplugs.
2. Stay away from loud environments.
3. Use devices that measure sound level. Smartwatches and smartphones may have apps and other functions to measure the environmental sound level.

Summary

Today, we explore how exposure to noises can affect our cognitive health. We found noise levels below 45 dB may be helpful for focus, but prolonged exposure to sound levels above 65 dB may increase stress levels that may be harmful. We also found that we could use smartwatches or smartphones to measure the environmental noise level and use earplugs to reduce the exposure. We hope this blog has helped you understand how noise affects our cognitive health!