Noise pollution at night can get to you. Very few people can sleep in the presence of noise, and even if they do, the noise can have a noticeable effect on the quality of sleep. If the noise occurs temporarily, it is annoying and sometimes exhausting. However, this stress can be dealt with – no long-term damage remains. Sleeping with earplugs can help with intermittent noise pollution. It becomes problematic if the nocturnal disturbance is permanent. Not only the psyche suffers, but physical damage can also follow.
The ear does not need sleep
The ear never sleeps, even at night. Even if we can’t consciously hear while we sleep, the ear receives signals and sends them to the brain. Only there a sound filter decides whether we perceive certain sounds. Evolution is to blame for the continuous operation of the ear. Because our ancestors couldn’t afford to completely shut down at night. The ear was virtually a life insurance policy against the dangers of the night. Even today, we are automatically put on alert when we wake up at night – the body reacts with stress.
The noise filter: some hear more, others less
It is astonishing that nocturnal noise is perceived completely differently from person to person. Some people manage to sleep undisturbed in noisy surroundings, while others are jolted out of sleep by even the slightest disturbing noise. Also, it depends entirely on what kind of noise needs to be processed. Mothers are a good example: they are usually particularly sensitive to their child’s voice, but can theoretically block out louder noises during sleep.
The fact that we deal with nighttime noise in such different ways has little to do with our individual hearing ability. The decisive factor is a noise filter in the brain that evaluates the signals from the nerves in the auditory system and decides whether a noise is passed on to our consciousness. If this noise filter has a lot of information to process, we do not necessarily wake up, but we can feel very exhausted the next day. Because the filtering process demands our energy reserves.
Meanwhile, researchers at Harvard Medical School have a guess as to what might be happening in the human brain during this filtering process. In the course of an experiment in a sleep laboratory, it was observed in people who were particularly good at filtering noise that the filtering process, in all likelihood, takes place in a part of the diencephalon – the thalamus. The signals probably do not even reach the cerebrum through the filter and are therefore not perceived. On the graphical representation of the EEG (electroencephalography), the presumed activities of the noise filter look like spindles. The researchers therefore christened them sleep spindles.
Continuous stress: when noise makes you sick
If you suffer from nocturnal disturbance of the peace while on vacation or temporarily at home because the neighbors are having a party, you don’t have to worry about long-term consequences. It’s a different story when there is constant disturbance of the peace at night. It can lead to chronic fatigue, increased irritability and a reduced performance capacity. According to the DGSM (German Society for Sleep Research and Sleep Medicine), other possible consequences are: depression, bronchitis, asthma, an increased risk of heart attack, thyroid dysfunction, gastritis or irritable bowel syndrome. Arthritis is also said to be favored by permanent disturbance of the peace at night.
In 2010, the Federal Environment Agency stated that road noise increases the risk of heart attack by 20% in one in six Germans. Experts suggest that noise pollution is now the third most avoidable cost to the health care system. The only thing worse would be smoking and excessive alcohol consumption. However, this calculation also takes into account the noise pollution during the day or, for example, at the workplace. Too much noise during the day can in turn have an additional negative effect on sleep quality.
Aircraft noise study: Nocturnal disturbance releases stress hormones
An experiment conducted by the Technical University of Berlin, which is now more than twenty years old, specifically investigated the influence of aircraft noise on sleep. The test subjects were exposed to the noise of a total of 32 take-offs and landings every night between midnight and four in the morning for six weeks. The volume is said to be equivalent to that in a bedroom of a resident near an airport.
Exposure to aircraft noise at night did not have a negative effect on every participant in the study. However, some of the test subjects showed clear signs of stress. For example, increased levels of the stress hormone cortisol were detected in the urine of these individuals. Initially, cortisol levels rose sharply, then dropped again. The organism of the test persons seemed to defend itself. After four weeks, however, the body capitulated to aircraft noise. Cortisol levels rose to unprecedented heights for the remaining two weeks of the experiment.
Such an elevated cortisol level is otherwise known mainly from people who have lost a loved one or had to deal with severe heartbreak. The body reacts to increased cortisol secretion with a kind of defeat reaction. This leads to a weakening of the immune system, which in turn paves the way for several possible secondary diseases. Increased cortisol levels alone add to the long list of possible health consequences an increased risk of stomach ulcers and high blood pressure. The cardiovascular system is therefore also said to age more quickly.
Aircraft noise pollution: Children and pre-stressed individuals particularly affected
For certain people, it looks like the body is buckling after an initial blockade from the aircraft noise. However, this was not the case for every participant in the study. People with chronic pre-existing conditions, older people and especially children are particularly susceptible – if only because they sleep longer. This conclusion was reached in the course of another study, the Munich Aircraft Noise Study. On the occasion of the relocation of Munich Airport, researchers took the opportunity to find out how the permanent aircraft noise pollution affected the local residents.
In children living near the new airport, researchers found that concentration and memory skills decreased slightly. Her urine showed elevated levels of stress hormones, including cortisol. Children who lived near the old airport and now had peace and quiet still showed flight-noise-induced performance losses in terms of concentration and memory 18 months later.
What to do in case of nocturnal disturbance?
Sleeping with aircraft or road noise at night is possible, but in the long run, there is a risk that your health will suffer. Affected persons should therefore look for ways to escape the noise in the long term. Soundproof windows are a first step to reduce the level. But no matter how much is invested in noise insulation, the source of the nightly noise nuisance cannot be fought by it.
A complaint to the responsible office, which can be the city, municipal or district administration, would be a further measure to combat aircraft or road noise. For this purpose, it is helpful to join forces with other affected persons. As argumentation statements of the WHO (World Health Organization) can be used. This indicates that the average noise level at night per year should not exceed 40 dB. Already from an average value of 55 dB noise can make ill.
Earplugs for sleeping only conditionally recommended
Hearing protection for sleeping is tempting. But the earplugs familiar from the drugstore are not for permanent use. This is a simple way to halve your personal noise level for comparatively little money. But precisely because they work so well, they should only be used temporarily. On the one hand, the ear gets used to the low volume – there is a risk of resulting hypersensitivity. On the other hand, constant wearing of earplugs can disturb the microclimate of the ear. This can cause bacteria to multiply or fungi to form. As a result, earwax production is stimulated as the ear attempts to cleanse itself. If you still use earplugs frequently, you should have your ear canal professionally cleaned and examined by an ENT specialist on a regular basis.
Minor disturbance of the peace: Noise is overpowering
Less piercing sounds, such as loud conversations on the floor above, can theoretically be drowned out. In the interests of sleep hygiene, however, experts do not recommend abusing the television or the music system as a means of helping you fall asleep. Music or a running TV also have a negative effect on the quality of sleep. If you still can’t resist using this artificial background noise as a means to an end from time to time, you should make sure that the noise source switches itself off after a certain time with the help of a timer.
When it comes to the supersonic of quieter sounds, from the perspective of a professional, if at all, only white noise comes into question. This is an artificially generated noise that is equally loud at every frequency. In practice it sounds like an indefinable noise. The absolutely constant monotony of white noise has a relaxing effect on many people.
Snoring: Learning to block out noise
If your partner snores regularly, this can be very stressful. Because earplugs are not a permanent solution, some experts advise autosuggestive exercises. Basically, it’s about teaching your own brain that snoring should not be viewed negatively. This may sound strange, but in practice it should work for some people. This can be done, for example, by silently telling yourself before going to bed that snoring is not dangerous and that it is just your partner’s sleeping noise. However, it may take a while for the autosuggestive exercises to take effect. Experts therefore advise extensive physical activity during the day in the acclimatization phase. If you get a good workout with sports, you leave your body with little choice but to get to sleep quickly.
Good noise, bad noise: constant noise instead of sudden noise
The nocturnal peace is only really disturbed when sudden noise is involved. For a restful sleep, noise backgrounds with a particularly high dynamic should be avoided above all. In acoustics, dynamics describes the difference between the softest and loudest sound – in a music recording, for example. A classical orchestra concert usually has very high dynamics. Due to the constant take-offs and landings at and around an airport, which sound very loudly and abruptly and disappear again, the background noise there also has a high dynamic and is therefore sleep-disturbing.
However, if you are on an airplane and try to sleep during the flight, there is a good chance that you will succeed in doing so. Because even if the background noise inside an airplane can be very loud, the dynamics of the noise level generated is not very high. The constant buzzing or hissing can even have a calming effect. This phenomenon also makes use of white noise, which can be used as an app, music file or CD to help you fall asleep.
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