Bubble of silence: how to protect yourself from noise
Noise is not customary to be afraid of as other types of pollution - for example, toxic particles of soot in the air. And in vain: according to WHO, noise pollution is the second health risk factor after air pollution. Our ears are not designed for the load that falls on them in the city: we evolved, listening to the sounds of the natural environment, in the range from 16 Hz to 20 kHz. The roar of machines, the noise of industrial equipment and the buzz of the crowd are acoustic vibrations that go far beyond this range, too aggressive for human hearing.
Noisy spaces seriously affect health. In addition to obvious hearing impairment, a long stay in busy city streets or in rooms where cars work or people speak loudly is fraught with increased pressure and an increased risk of coronary heart disease; a long stay of pregnant women in a noisy environment is associated with a number of fetal malformations. Noise also affects the ability to concentrate: in experiments conducted by psychologists from Cornell University, children who studied in noisy classes received lower grades than those who studied in silence.
Protecting yourself from noise means protecting your health, improving concentration, less tired and generally improving the quality of life. You can do this in three ways: to move away from city noise, equip your home and workplace with soundproof materials, or put on noise canceling headphones. You can choose a quieter place on this map of noise pollution in Moscow and the world, experts will help you choose suitable materials for the walls, and you will have to choose your own headphones.
Map of Moscow noise pollution
World Noise Pollution Map
What you need to know in order to choose noise canceling headphones
Let's start with the simplest. There are two types of noise reduction: passive and active. Passive is simply soundproofing using materials in which the sound wave propagates very poorly. Multilayer structures work well, they absorb waves of different lengths, and porous materials in which sound encounters obstacles many times. Active noise cancellation is a more complicated thing: the point is to generate a wave that will interfere with the wave of unwanted sound. When the waves interfere, they turn into one with a greater or lesser amplitude. For active noise reduction, of course, a smaller amplitude is needed - such that the resulting wave is beyond hearing.