Man-made noise in our living environments

摘要

The ITU's (International Telecommunication Union's) man-made noise levels are based on measurements performed in the 1970s. Some measurements have been carried out since then, showing that noise caused by automotive ignition systems has been reduced, but man-made noise in business areas and city centers increased, especially due to the widespread use of electronic systems. The interference scenario also changed, from analog communication systems in relatively free-space conditions, to digital systems in living areas, often semi-enclosed such as offices, industrial production plants, and even inside cars and trains. Several measurements have therefore been carried out to estimate the level of man-made noise in these semi-enclosed environments.