Annoyance and acceptability judgements of noise produced by four types of aircraft modifications

The effects of 32 different experimental aircraft noise conditions were judged on a 0–9 annoyance scale by 384 subjects. Noise levels accounted for half of all explained annoyance variance, with level A, close area noises, averaging 2.22 greater annoyance than distant area noises. The correlation between Leaq, and 1536 annoyance judgements was r=0.53, with five points of Leaq associated with a one point annoyance change. The overall annoyance reduction due to abatement programs was 1.43. However, annoyance with level A, after abatement, was still 6.23 compared to 7.53 for noise without abatement. While this represents substantial annoyance reduction, only one-third felt level A after abatement, was acceptable, but in level B, after abatement, annoyance was 3.99, acceptable to 80% of all residents. Annoyance under TV conditions was consistently greater than noise judgements under rest relaxation, averaging 1.02 points greater annoyance. Likewise, subjects with residence in distant areas judged all noises more annoying than close area residents, averaging 0.83 greater annoyance for level A and 0.53 greater annoyance for their own level B noise.