The impact of noise on the Sleep Cycle

Sleep is an integral part of life, yet its nature can be complex to comprehend. Sleep occurs in cycles, stages and patterns that vary from person to person – making it a process that’s hard to explain precisely why some people sleep better than others.

One factor that is known to impact on sleep is noise; the number of people this affects can vary depending on location, living environment, and individual sensitivity to noise. Those that live in an urban area, near a transportation hub or places with high population density are more likely exposed to noise pollution and so the greater prevalence of sleep disturbances due to noise. In the UK, a survey conducted by The Sleep Council found that 31% of respondents were regularly disturbed by noise at night. In the U.S., figures from the National Sleep Foundation (2020) suggested that 23% of Americans often or always have trouble sleeping due to noise.

How does noise impact our sleep?

When we sleep, we enter the sleep cycle, a recurring pattern of sleep stages. It is composed of two main types of sleep: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep. Each sleep cycle consists of multiple stages of NREM sleep followed by a REM sleep stage which we will explain in further detail below:

1. Stage 1 NREM Sleep (Light Sleep): This is the transition between wakefulness and sleep. It’s a brief stage lasting a few minutes. During this stage, muscle activity decreases, and eye movements slow down. It’s relatively easy to wake up from this stage, meaning noise can disrupt it
2. Stage 2 NREM Sleep (Light to moderate sleep): This stage accounts for a significant portion of total sleep time. Eye movements cease, heart rate and body temperature decrease, and brain activity continues to slow down. Disruptions from noise during this stage can lead to brief awakenings
3. Stage 3 NREM Sleep (Deep Sleep): This is the deepest stage of NREM sleep, and is crucial for physical restoration and growth, as well as memory consolidation. During this stage it is more difficult to wake up from external stimuli like noise
4. REM Sleep (Rapid Eye Movement Sleep): REM sleep is characterised by rapid eye movement, increased brain activity and vivid dreams. It plays a crucial role in cognitive function, emotional regulation and memory processing. External noise can still influence REM sleep, although it may be less disruptive compared to NREM sleep stages

As our hearing has no off-switch, noise disturbances, especially during the early stages of sleep (Stage 1 and Stage 2), can delay the onset of sleep. The brain remains in a more alert state in response to noise, making it harder to transition into deeper sleep stages. Noise can also lead to frequent brief awakenings throughout the night, disrupting the continuity of sleep cycles and preventing you from getting sufficient deep and REM sleep.

Why is it important to get a good night’s sleep?

Getting enough sleep isn’t only about total hours of sleep. It’s also important to get good-quality sleep on a regular schedule so you feel rested when you wake up. For optimal sleep quality, you need the proper amount of time in each stage and cycle. This includes deep sleep, stages three and four, when your body repairs itself. At this stage, your brain releases growth hormones and other chemicals to repair organs and muscles. Additionally, it boosts your immunity while giving you energy for the day ahead. Without enough ‘proper’ i.e. deep sleep, your body is not having the chance to repair itself and you’ll likely wake up in the morning feeling flat and unmotivated. It could affect your attention span, concentration, strategic thinking, assessment of risk and your reaction times. This is important if you have a big decision to make, are driving, or are operating heavy machinery, because sleep deprivation makes you more likely to make a mistake or have an accident. But getting plenty of sleep can help you to stay sharp and focused all day long.

During sleep, your body performs many important repair and maintenance processes. These include restoring hormone balance, eliminating waste products, and creating memories. At night, your body secretes cytokines that strengthen your immune system’s capacity for fighting infection. A chronic lack of sleep may leave you more susceptible to colds and other illnesses, so making sure you get enough rest is essential for staying healthy. Additionally, when you are ill, make sure you rest and take it easy to allow your body to focus its energy on fighting the illness and ensure you get better as quickly as possible.

Most adults need 7 or more hours of good-quality sleep on a regular schedule each night. Kids need even more sleep than adults:

• Teenagers – 8 to 10 hours of sleep each night
• School-aged children – 9 to 12 hours of sleep each night
• Pre-schoolers – between 10 and 13 hours a day (including naps)
• Toddlers – between 11 and 14 hours a day (including naps)
• Babies – between 12 and 16 hours a day (including naps) – which we are guessing where the phrase ‘I slept like a baby comes from’ when describing a decent kip
• Newborns – between 14 and 17 hours a day

As well as quality sleep, a minimum quantity is required too. If you sleep less than 7 hours a night, you are more at risk of developing obesity. This is because getting enough sleep impacts on your hormones and motivation to exercise:

1. Hormones – For instance, sleep deprivation increases levels of ghrelin and decreases levels of leptin. Ghrelin is a hormone that makes us feel hungry while leptin makes us feel full. This may cause us to feel hungrier and overeat due to being tired
2. If you’re not sleeping properly, your body will need more energy because it’s awake for longer. But you’re more likely to overeat and choose foods that are high in calories later in the day (who doesn’t grab a chocolate bar for a little sugar-energy boost?). Unfortunately, these foods impact on your waistline

So, if noise is a factor impacting your ability to sleep, it is very important to find address this. The solution is sleeping earplugs.

How will SnugsZen sleeping earplugs help me?

There are range of sleep products and earplugs available on the market, however SnugsZen custom fit sleep plugs are the best choice and have numerous benefits compared to others:

1. Enhanced comfort. As they are moulded to the specific contours of your ears, you do not get pressure points or discomfort. This allows you to use them for many hours pain-free
2. Better noise reduction. Custom fit earplugs for sleeping offer superior noise reduction compared to standard, one-size-fits-all earplugs. The perfect fit provides a more effective seal in the ear canal which helps to block out a wider range of noises, including low-frequency sounds
3. Reuseable. SnugsZen are made from a medical grade silicone which is durable and will not degrade over time. Easy to clean, they can be re-used for many years. This makes them a cost-effective investment in the long run.
4. Reduced risk of irritation. Custom fit earplugs are less likely to cause irritation or sensitivity in the ear canal, as they are designed to fit your ears perfectly without causing friction or pressure points. Snugs are made from a hypoallergenic silicone ensuring no allergic reactions
5. Ideal for side sleepers. SnugsZen are designed to sit inside your ear canals with no protrusion from the ear. As they are moulded to your ear shape, they are comfortable to use, even when lying on your side

What other steps can I take to improve my sleep?

Noise is a factor which can impact on your sleep, however there are other stimuli and factors which may be hindering your sleep. Below are some ideas on how you can improve this.

1. Make your bedroom dark and cool, as these settings support natural temperature changes and hormonal shifts that lead up to sleep
2. Disconnecting from electronic devices like mobile phones or laptops for at least half an hour before bed can help you drift off more quickly and deeply into sleep
3. Ensure you set boundaries on when you go to sleep and set alarms for 7- 9 hours after falling asleep. Avoid temptation to catch up on lost sleep from the night before as this can ruin your pattern. Soon, your brain will be programmed and establish its own internal body clock. Follow a sleep routine that helps regulate your body’s internal clock and go to bed at the same time every night
4. From an employer’s perspective, you could look to incorporating good sleep strategy into your employee’s working day, to ensure optimal productivity and focus. These could include nap rooms or pods for workers to catch up on rest during mid-shift. Other initiatives include wellness and stress management workshops emphasizing the significance of maintaining a regular bedtime schedule, healthy eating habits and exercise regimens