Environmental acoustics and noise maps

Acoustics is a branch of physics that studies the sounds, infrasounds and ultrasounds that propagate through matter. Production, transmission and storage are studied, as well as the perception or reproduction of sound. Within this branch of physics is environmental acoustics, which is the one that studies sound outdoors, environmental noise and also its effects on people and nature. Noise sources such as traffic, planes, trains, ships, factories, environments where noise is produced such as workshops, as well as entertainment venues, stadiums or even parks, for example, are also studied.

What are noise maps?

One of the tasks carried out within environmental acoustics is the creation of noise maps, the cartographic representation of a given area in terms of noise levels. With this, it is possible to determine the level or levels of noise to which a certain group of people is exposed. Thanks to this information, different plans and strategies can be developed whose main purpose is to be able to prevent and reduce environmental noise, especially when its levels can become harmful to the Health. Provided that all the data that has been collected in the study is correctly interpreted, the intervals of the measurements can be differentiated, being able to detect which are the main acoustic contaminants in order to reduce them with a correct attack strategy. If we look at how noise is represented in a map of these characteristics, it can be recognized in several ways, by means of isophones and colors. The isophones are lines that join points where the sound pressure levels are equal. In the case of points where the sound pressure level is the same, they are represented with the same color. This class of maps is made in two ways, one by sample and the other by simulation. In this second case, it is done with a technique that is responsible for digitizing the noise through the use of the sound level meter. It is a device that can measure noise pollution in large spaces and the study is carried out in different periods of time in certain periods of time to obtain acoustic references with which to obtain reliable data. For the preparation of these maps it is necessary to recognize the noise sources, which are necessary to be able to take measurements. In this case, two strategies are used, one is noise level maps, which are those that measure noise densities. On the other hand, noise exposure maps are those that are directly focused on evaluating buildings and homes that are exposed to various noise levels. We must not forget the importance of making noise maps as accurate as possible, since this is essential to be able to take actions to combat noise, trying to reduce it as much as possible, with the benefits that this brings.