We don’t tend to think of noise pollution in the same way as we do air pollution. Noise pollution, which describes the excessive noise we associate with city life – traffic, construction, industry, people going about their daily lives – is seen as a cause of irritation and sometimes anger, but beyond that we don’t regard it as doing us any actual physical harm.
Yet a recent study by German company Mimi Hearing Technologies has revealed that noise pollution does us more damage than we realise. Using data from 200,000 people across the world, the survey discovered that those who live in noisy cities are more likely to suffer hearing loss. By administering a hearing test via mobile phone, they calculated that people in the loudest cities were, on average, ten years ‘older’ in terms of their hearing than those in the quietest cities.
The cities topping the list as the most cacophonous include Cairo, New Delhi Istanbul and Paris, while those least affected by noise pollution were places such as Zurich, Vienna, Oslo and Munich.
According to the World Health Organisation, there is a cost to this too – around $750billion globally, what with medical bills, lost earnings and other related problems when people lose their hearing. And that’s before we consider other effects of excessive noise, like stress, fatigue and the poor quality of our sleep.
So what can be done? For starters, reducing the volume of traffic in big cities. In Paris they have already experimented with concepts like a ‘day without cars’, where one day in the month 30% of the capital becomes off-limits to vehicles. The reduction in noise, as well as air pollution is profound, sound levels in the city centre dropping by half.
Another long-term solution will be the increasing use of Electric Vehicles (EVs) on the roads. As well as being better for the environment, EVs make very little noise at all, and with purchasing and running costs expected to become lower than petrol or diesel cars by 2022, the traffic could be reduced to a comforting hum pretty soon.
Citizens can do their bit too, by transforming their smartphones into sound meters. Researchers at the Free University of Brussels in Belgium have developed the NoiseTube app, which enables users to monitor where and at what times the decibel levels are highest in the city.
A detailed ‘noise map’ is then produced and made available to users, who can avoid areas of high noise pollution. In the meantime, the data is used by city councils to target noisier areas more effectively, using sound absorbent materials like foam and fiberglass precisely where it is needed the most.
The Listening NYC app by Umbrellium brings a similar idea to New York, with the added bonus that users can rate and describe sounds – so if you want to go somewhere in the city with a high concentration of bird calls, the app lets you know where to go.
There are also new technologies taking shape, designed to tackle the scourge of unwanted noise in the city environment. Silentium is a company that aims to tackle noise reduction through innovation, and we could see variations of its Comfort Shell on our city streets soon enough.
The Shell is a giant helmet-shaped object positioned above the head which drastically reduces noise, making it a good place for a quiet conversation on your phone or simply somewhere to take a breather. The company also pioneers Quiet-Bubble technology, which uses microchip technology embedded into headrests to create ‘anti-noise’, effectively cancelling out incoming noise and creating a protective bubble around the head.
Finally, radical new materials are being developed by quantum engineers at the Swiss Federal Institute of Technology in Zurich, which could provide hitherto unimaginable forms of sound proofing in the future. It might seem like science fiction, but such materials could allow noise to pass in one direction only, rather than reverberate around and through objects.
Operating on a sub-atomic level, it exploits what are known as ‘edge states’, whereby particles flow along the edge of a material without penetrating the inside. In practical terms, this means it could provide incredible insulation against sound vibrations, as well as concentrating them in much the same way a lens focuses light.
Such technology might be some way off commercial applications as yet, but it marks a shift in approach to noise pollution, and combined with citizen activism, increased EV usage and a more mindful attitude to how we are affected by the sounds around us, it is putting city life on the cusp of a ‘quiet revolution’.