Most of us are used to sounds - even loud ones - in our environment. However, we often do not realize that noise has a detrimental effect on our health as well as the natural environment. The increasing noise level in the surroundings is already treated in terms of pollution, just like other sources of air pollution. Students from different countries will perform noise measurements in their cities. We will determine the real level of noise pollution in busy city outlets, quiet city districts and recreation parks. Together, we compare the results of measurements in different countries. Then, together, we will consider the consequences of large noise and the ways of eliminating noise from the lives of people in cities.