Comparison of advanced turboprop and conventional jet and propeller aircraft flyover noise annoyance

Abstract

A laboratory experiment was conducted to compare the annoyance to advanced turboprop aircraft flyover noise with the annoyance to conventional turboprop and jet aircraft flyover noise. The effects of fundamental frequency and tone‐to‐broadband noise ratio on advanced turboprop annoyance were also examined. A computer synthesis system was used to generate 18 realistic, time varying simulations of propeller aircraft takeoff noise in which the harmonic content was systematically varied to represent the factorial combinations of six fundamental frequencies ranging from 67.5–292.5 Hz and three tone‐to‐broadband noise ratios of 0, 15, and 30 dB. These advanced turboprop simulations along with recordings of five conventional turboprop takeoffs and five conventional jet takeoffs were presented at D‐weighted sound pressure levels of 70, 80, and 90 dB to 32 subjects in an anechoic chamber. Analyses of the subjects' annoyance judgments compare the three categories of aircraft and examine the effects of the differences in harmonic content among the advanced turboprop noises. The annoyance prediction ability of various noise measurement procedures and corrections is also examined.