Environmental noise can be defined as the complex of audible sounds that causes disturbance, impairment or health damage. The study of environmental noise in cities is not an easy matter. There are many concurrent sources and noise assessment can be performed in various possible ways. Measurement campaign, monitoring and calculation can be addressed either to produce noise maps regarding the acoustic classification of territory or to protect residents and other citizens from exposure to noise levels higher to fixed limit values. Sources and receivers are often combined in complex scenarios, making modeling of noise propagation and design of solutions a quite complicated job for acousticians and policy makers. From the receivers point of view, it is well known that long lasting exposure to noise causes health effects that could be temporary or permanent. There are different effects of noise on people, and different degrees of severity depending on individuals experience. Noise can disturb human activities, by causing distraction or by physically interfering with it. Typical effects of exposure to urban noise are annoyance, mental health effects, cardiovascular and other physiological effects, sleep disturbance and insomnia, cognitive effects on children, distraction, speech interference, disruption of work and mental activity. Besides and linked to these harmful effects, there are social costs in workplaces and living places as well (healthcare, absence through illness, accidents caused by tiredness related to insomnia or sleep disturbance, depreciation of real estate, production loss).
The main cause of exposure to noise and its negative effects in cities is traffic and more in general transportation system. In this paper some freshly produced data and some case experiences are reported, with a general reference to EU Legislation and the state of art of its application, in particular for what concerns Noise Mapping and Action Planning regarding noise from transport infrastructures.