Abstract

Tonal noise is produced by bodies rotating at high speeds such as helicopters. Sounds of the same amplitude will produce different responses depending on the tonal content of the sound. Previous studies suggest that tonal noise is more annoying than broadband noise. Nowadays, sound level meters that can detect tonal noise directly are available in the market, but they are very expensive and beyond the reach of most environmental noise researchers. Hence, the need to adopt an analytical method that can be used to analyze and detect the presence of pure tones in helicopter flyover noise. This paper employs the simplified method suggested by the International Organization for Standardization (ISO).