Assessment of Helicopter Noise Annoyance: a Comparison Between Noise from Helicopters and from Jet Aircraft

A laboratory study has been conducted to validate the special procedure recommended by Norwegian authorities for assessing helicopter noise annoyance. Noise from helicopters has been subjectively compared with noise from a modern commercial fixed wing jet aircraft. At equal noise levels, LEQ, the noise from a helicopter is judged more or less annoying than the noise from the reference aircraft, depending on the type of helicopter. Norwegian procedures call for a 5 dB "penalty" when judging the annoyance of noise from helicopters. Based on the conclusion of the present study, it is recommended that the same procedures for assessing conventional aircraft noise annoyance be used for both fixed wing and rotary wing aircraft without any correction factors.