Study on Evaluation of Airplane Noise

─Quantitative Consideration on Effect of Difference between Airplane Noise and Background Noise Level ─

Abstract

It is generally agreed that the sensuous noise level is influenced by background noise. However, there are little quantitative papers on this issue, and this point has been ignored when the airplane noise was evaluated. Therefore, it is desired to clear dependency of sensuous noise level on the difference between airplane and background noise levels and to induce a compensation formula. For this purpose, the airplane and background noise situation at the north part of Narita International Airport is investigated. Combined with the result of questionnaire survey in the same area, the tendency that habitants in quiet area fill higher noise level is confirmed. And an experiment on sensuous level using recorded airplane sound is made and it is shown that the subjects fill the noise level approximately 1.5 dB higher per 10 dB differences between airplane and background noise levels. And, it is shown that WECPNLs reevaluated by relationship clarified in this experiment become 3 point graters in quiet area.