Noise has become a concern for increasing numbers of national authorities during the past decade. The main sources of acoustic nuisances are road, rail and air transport, recreational activities and industry, but people also complain more about noise from their neighbours.
A considerable number of people are exposed to levels of traffic noise that cause not only serious annoyance and sleep loss but also communication problems, and even learning problems in children. There is emerging evidence of an association between hypertension and ischaemic heart diseases and high levels of noise. Ambient noise levels continue to grow due to ever-increasing volumes of traffic.
Noise legislation has been passed in various countries to regulate vehicle, aeroplane, and industrial noise. Typically, the noise threshold is around 55 decibels (dB), and the irritation threshold is 65 dB. Switzerland spends the most on acoustic problems in buildings in Europe.