Annoyance from nocturnal aircraft noise exposure: Laboratory and field-specific dose-response curves

Kurzfassung

Dose-response curves regarding the annoying impact of nocturnal aircraft noise were calculated for the (1) maximum noise level L_AS,max combined with the number of aircraft noise events and for the (2) energy equivalent noise level L_{AS,eq event} by means of random effects logistic regression. These parameters were compared according to their predictive properties for annoyance ratings. Questionnaire surveys with 128 subjects of a laboratory study performed at the DLR Institute of Aerospace Medicine served as data basis. The laboratory results were compared to the results of a field study carried out with 64 airport residents living in the vicinity of the Airport Cologne/Bonn. In the laboratory setting there was a significant rise of the portion of annoyed people depending on L_AS,max and frequency of fly-overs. Unlike previous studies, the percent annoyed by aircraft noise also increased with L_AS,max in nights with less than 16, but louder aircraft noise events. The group of annoyed subjects also significantly increased with the L_{AS,eq event}; however, above 50 dBA it decreased again since fewer but louder events were presented in the underlying combinations of noise level (45 to 80 dBA L_AS,max) and number of noise events per night (4 to 128). Data from the field study confirmed the trend of the laboratory dose-response relationships. Nevertheless, the curves established in the laboratory lay above the field-specific curves, i.e., subjects felt more annoyed by aircraft noise in the laboratory setting than in their domestic environment. This was most probably caused by the increased number of awakenings in the laboratory compared to field conditions. The findings of the studies indicate that not only the energy equivalent noise level, as used in noise abatement rules of many countries, but also the number of aircraft events are a major source of nocturnal aircraft noise induced annoyance.