Considering the influence of the sound source noticeability on aircraft noise annoyance

This paper considers a possibility to mitigate noise annoyance due to low-level but highly frequent flyover noise exposure from a viewpoint of reduction of the noticeability of the sound source. Despite the remarkable sound reduction at the source, there are still a lot of complaints about aircraft noise. People living near the flight path, even if far from the airport, also make complaints about aircraft flying just overhead. In Tokyo metropolitan city, airport capacity expansion by introducing new flying routes over the city area is planned to prepare for the Olympics being held in 2020. Thus, it is urgent to resolve such complaints and to prevent outbreak of serious noise disputes beforehand. This paper looks back on such issues of complaints happened in Japan and discusses a possibility to mitigate noise annoyance by reducing the frequency people may feel aircraft flying overhead through flight route controlling.