Noise Sensitivity & the Temporality of Noise

Abstract

The noise from an aircraft overflight is one of the most prevalent and disturbing forms of transportation noise. Public annoyance in response to aircraft overflight noise has increased over the years, despite the sound outputs of individual aircraft reducing. One theory is that this is due to the increasing number of overflight events. To understand this more, and to explore the role of noise sensitivity (NS) and annoyance to aircraft noise, a laboratory experiment was designed. Comparisons between the impact of a single high-level (80 dB Leq) overflight and multiple moderate-level (60 dB Leq) overflights were made in terms of: psychoacoustic perception (loudness and annoyance), cognitive task performance and physiological reactions (blood volume pulse amplitude, skin conductance and heart rate). Furthermore, the role of NS as a moderator of effects was explored. Three different measures of NS were used: the NoiSeQ questionnaire, a single-item three-point rating scale, and the loudness discomfort level. Results showed that higher-NS individuals were more susceptible to the impacts of aircraft overflight noise. Those with higher NS perceived aircraft to be louder but not more annoying than people with lower NS. Those with higher NS also performed worse on a cognitive task assessing mental arithmetic, working memory, attention and concentration, when exposed to noise. Moreover, greater physiological arousal was observed in NS individuals, indexed by skin conductance and heart rate. The single high-level overflight had more impact than the multiple moderate-level overflights, as shown by greater physiological arousal, perception of loudness and annoyance. In the present study, the greater impact by the single high-level overflight suggests that when there is a greater difference between aircraft noise levels, individual largely weighs the overflight noise level when judging psychoacoustic reactions. However, previous research has suggested that when overflight noise levels are closer together, psychoacoustic perception was based on the number of overflights. Further research is required to ascertain the trade-off between overflight noise level and the number of events as this may explain why individuals are more annoyed by a given level of aircraft noise exposure than was observed in the past.