Contribution of airports to noise in surrounding environment; identification and measurement of noise sources

This paper describes the results of an experimental campaign carried out near the Milan Malpensa airport. Aim of the work was the determination of new parameters or measurements that can be used in order to deeply characterize the acoustic field in aeroportual environment. The most innovative aspect is the use of a three dimensional sound intensity probe, that allows determining the direction of the acoustic energy flow and consequently making assessments about the noise source position. Data has been statistically analyzed with sound intensity polar diagrams, which represent the direction of sound (as a function of frequency) coming from the surroundings toward the experimental site. These diagrams allow determining which is the direction from which most of the acoustic energy comes from and can be used, for example, in order to optimize active or passive noise control procedures.