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When Does Noise Become Noxious? On the right to hear what we want

Read more Last updated: October 2020
In collection Hearing
Reading duration: 5 minutes

We all know that noise can make us ill. But does it also harm our prosperity and development?

Noise is undesirable sound

The thing looks like a large frying pan with a diameter of a good metre, about 20 centimetres thick, with large handles on it. Just for fun someone welded the pan to a tripod and attached it to the railing of a large ship.

We are talking here about a Long Range Acoustic Device (LRAD), colloquially sound cannon. Shipping companies, also coast guards, naval and police units, use the LRAD as a non-lethal weapon against pirates and terrorists. The LRAD generates a series of shrill soundwaves in the range of up to 3100 Hertz - arriving at the target with a sound pressure level of around 150 decibels. A starting jet brings it to considerably less, "only" 120 decibels, also the level where the pain threshold begins for most people. The US Army used sound cannons like this at distances of several hundred metres in the second Iraq war to crack enemy positions and tanks whose crews immediately surrendered to the deafening noise. Almost routinely, security authorities around the world use LRADs to disperse violent demonstrations. So when the authorities finally restore "peace and order" during "disorder", one can increasingly take that verbatim.


The origin of the German word "Lärm" (noise) also demonstrates this wonderfully. It comes from the Italian "all'arme", which means "to the weapons" and is also unmistakably the source of the word "alarm". More than 80 years ago the everyday intellectual Kurt Tucholsky defined noise as: "the sound of others." What a clever thought. Because what we perceive as too loud depends only to a very limited extent on how loud it actually is.

The key is whether we want to or have to hear it. A sound cannon always hurts -but there are people who hear 110 decibels at pop concerts and find it pleasurable. Neighbours, on the other hand, only need a fraction of that to call the police. It is clear that noise can make you ill, for example there are more heart attacks and strokes due to aircraft noise. This is not propaganda from anti-technology eco warriors, but a scientifically proven fact from numerous studies. Today, occupational physicians define the stress levels at 55 decibels. What lies beyond that is too loud. Physically, 55 decibels is not much. But it is the "sound of others" which makes the difference. This is a psychological, an individual matter. Pure norms don’t mean much here. The World Health Organization (WHO) has even declared noise to be the greatest environmental hazard after air pollution.

What is Noise?

All sounds are vibrations, so there is no physical difference between noise and pleasant sounds.

What is different however is how listeners respond. Noise is simply any sound the listener does not want to hear. Hearing professionals call this listener intent. This means, a single sound can be both: noise, or not. Depending on how the listener wants to hear it.


Sounds, noise and our hearing sense

Our hearing processes sounds and noise in a special way. However, if a certain degree of hearing loss occurs, "normal" processing is no longer possible. This is where hearing implants may help. The implant's external part, the audio processor, collects the sound or noise, and a special technology even helps to reduce noise.

Learn more

Much ado about nothing?

Does man have a right to peace and quiet? To hear what only he or she wants? This question seems a little odd because our culture has concentrated much more on the visual over the last hundred years and acoustics have often been left on the sidelines. Photo, film, video, the fast, colourful, garish visual appeal - that was the focus in the 20th century. When The Bangles sang "Video killed the Radio Star" in 1979, the deed had already been done: hearing was considered secondary. But this is set to change fundamentally in the 21st century. One reason for this is the massive health damage caused by noise, especially in urban areas, in the world's large cities and swelling megacities, whose populations are growing by tens of millions. The great physician Robert Koch predicted 100 years ago that noise would play the same role in the future as „plague and cholera“ did in the past, and that mankind would have to "fight this relentlessly".

A surprisingly far-sighted prediction. Koch was thinking about health. But the issue is also one of prosperity and its indispensable foundation, knowledge.

In his remarkable "London" biography, the English author Peter Ackroyd named one chapter "The Noise of the City" and, using London as an example, described what used to apply and continues to apply to every city, namely that "at all times its noise was a key characteristic", "which, among other factors, constitutes the unhealthy nature of the city - and also the unnatural, like the roar of a terrible creature. But this noise is a sign of vitality and strength". How aptly observed.

Big city noises
Loud cities: soon to become a synonym for poor cities.
© Getty Images

Wealthy cities of the Middle Ages were noisy. There was much business being done, loud merchants, loud church bells, and many horse-drawn carriages, which caused a hell of a noise on the streets. Later during the age of industry this intensified: steam hammers, machines, engines filled every room. Our cities are still built in this spirit. But industry is no longer the most important employer in developed OECD countries. Most people earn their living in the knowledge sector. This is work that requires concentration. Knowledge work and the sounds of others. Two polar opposites, like fire and ice.

A few years ago, the American neuroscientist Shelly Carson conducted an experiment with students. One test group consisted of highly talented, creative students, the best in their year, while the other group was extremely mediocre. Both groups were brought into the same room and given the task of solving some written problems in their specialist field. As soon as the test started, hidden loudspeakers began to make noise. While the mediocre students delivered average results, the particularly good students failed miserably. Ergo, it's easier to trip smart people up by making noise. They perceive more. That's why they find more solutions to open questions, know more and recognise connections that others don't even notice.

The power of silence

We can draw direct conclusions from this: Where it is too loud, less thinking is achieved. Economic power lies in the peace and quiet. If it rattles and crashes, on the other hand, the knowledge society has yet to arrive. Loud cities will soon be synonymous with poor cities. Where there is no knowledge, there will be no prosperity. It's that simple.

We will have to learn that noise harassment is not a trivial offence and that people who feel disturbed by the "sound of others" are not "bourgeois". We will need new cities, different mobility, new infrastructures and different architecture for the coexistence of life and knowledge.

The right to hear what one wants will become a gigantic investment project in the 21st century. It will bring peace and order to the knowledge society. Let’s see how good that sounds.


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