Field acoustical measurements for sound insulation residences against aircraft noise

In this paper, we have investigated measurement methods of the sound insulation performance for residences treated with increased sound insulation near airports in Japan. The flyover measurement method and the loudspeaker measurement method are conducted to verify the performance. The first one provides the performance of the whole facades of a house using aircraft noise, approximately similar to the FAA method described in ASTM E966. The pressure level outdoors is measured at enough high position to ignore the interference with sound from the ground or the house roof. However, the microphone is sometimes put on the roof surface because of being in the house's shadow in the overcrowded residential area. Thus, we have investigated the sound pressure level difference between the high and surface positions using simple numerical analysis and field measurement. On the other hand, the outdoor and indoor loudspeaker methods are conducted for facade elements such as windows and doors, according to JIS A 1520. The sound insulation performance for facade walls is also measured with ISO 16283-3; however, the loudspeaker sometimes cannot be positioned far enough from the wall. Thus, we have proposed the measuring method for the facade wall by applying the indoor loudspeaker method.