We have all had those sleepless nights, woken up to the screams and shouts of the party-loving neighbours. Such sounds which may seem trivial during the day can become irritating during the night. But did you know that even the low-level noise such as the sound of a busy road is enough to rob you of crucial sleeping hours without actually waking you up?
Worryingly, the WHO has found that one in five Europeans are exposed to such sound levels at night. Long term exposure to low levels of noise has shown to contribute to the development of insomnia and cardiovascular diseases.
What is the role of noise in our sleep?
Our ability to hear helps us to socialize, work and communicate with the outside world. It also keeps us safe by allowing us to recognize important signals that highlight danger, that are usually sudden and loud.
However as we sleep, our ability to hear weakens. This is because a special region of the brain called the thalamus which acts as a gatekeeper to our consciousness and sleep, partially closes its door to sounds at night. This allows us to then relax, fall asleep and stay asleep.
From an evolutionary point of view, to become completely oblivious to sounds would not provide any advantage to our survival. With our eyes closed we rely heavily on our ability to hear to inform us of any danger especially with increased sensitivity during the light and REM stage of our sleep.
This is why sirens and alarms are designed to have a jarring effect. The body responds to loud and sudden sounds by activating your sympathetic nervous system. This is the body’s fight or flight mechanism which allows you to become alert and aroused, ready to deal with the threat.
But our sensitivity to sound during sleep varies from person to another, with some able to sleep through their alarms, whilst others waking up to a pin drop. This is because the so called ‘sound sleepers’ have brains that can generate more “sleep spindles”. Sleep spindles are specific brain waves where the frequency of it determines the extent of how soundproof your brain is to external sounds.
Interestingly, different types of sounds can also change how open our gate it. For example, the sound of a crying child will wake up a mother even if she sleeps through her morning alarms. This is because our brains can also recognise sounds that elicit emotions.
Impact on sleep
If you live in a noisy environment then our sound gates are continually being pushed open. This has shown to have a huge negative impact on our sleep. This explains why residents who live near an airport, report much higher insomnia rates and excessive daytime sleepiness, compared to those who are not exposed to aircraft noise.
Noise during the night, whether it is loud, quiet, high frequency or low, all stimulate our brain regardless and reduce the quality of our sleep. Considering that sound plays a danger-detection role during our sleep, it comes to no surprise that long term exposure to noise, which is equivalent to constantly waking up from the sounds of a growling tiger, places our body on constant alert , or in a “flight or fight mode” . As such, long term exposure to sound during the night has been associated to high blood pressure and subsequent cardiovascular disease.
The effect of noise pollution, which is one of the most problematic environmental causes of health problems, has resulted in a loss of one million years of “healthy life” for Western Europeans. It is therefore important to control the amount of noise you are exposed to during the night. In most cases we cannot remove the source of noise, whether this is the snoring partner or the busy motorway. Therefore, adapting your bedroom environment is the easiest and quickest way to help improve the quality of your sleep.
Make your bedroom a cocoon
Remember, sounds travel by bouncing off objects. The more your bedroom objects can absorb the material, the less sound will go into your ear. Invest in soft furnishing (e.g. heavy curtains, thick carpets) that absorb the sound. If you have neighbours who throw crazy parties every other night, noise cancelling plaster boards on walls and soundproofing materials under the floors can help create that silent cocoon.
Block your ears
If its your partner snoring that's preventing you getting your good quality sleep, you can use earplugs or noise cancelling headphones.
Mask the sounds
Did you know there are different types of sounds? White noise is a special type of sound that helps masks background sounds. It is similar to the static sounds that was common from older television sets that had no signal. Although, there are many machines and apps that provide this specific sound signal, a running fan also provides this kind of patternless noise.
Listen to calming music
Lullabies are not just for children. Music has a powerful effect on your mood by releasing lots of “feel-good hormones”. This in turn, relaxes your body and helps you get to sleep. You can also opt to listen to sounds that reflect the soothing sounds of nature.
Change the way you relate to sound
Often, it is not the actual noise that is the problem, but the noise (inside your head) about the noise. For example, “I know my noisy neighbour is going to come home soon” or “I know he’ll start snoring soon”.
It can therefore be helpful to describe the sound of the noise objectively as you hear it such as “I can hear a rattle, a snort, a whisper, a wheeze” or “It starts soft and gets loud”. Describing it in this objective and non judgmental way releases you from its emotional grip and increases the chance of actually sleeping.