Do short-term temporal variations of noise exposure explain variance of noise annoyance?

It has long been suggested that, in addition to energetic measures, the effects of noise can be better explained by considering the variation of noise level over time and the frequency distribution of event-related acoustic measures, e.g. the maximum sound pressure level. To this end, a new acoustic descriptor called Intermittency Ratio (IR) has been developed within the framework of the SiRENE study (Short and long-term Effects of Transportation Noise Exposure). It reflects the eventfulness of a noise exposure situation and may be used as an additional exposure descriptor alongside established metrics like the Leq. In the SiRENE study it is hypothesized that the new metric can explain additional variance of noise effects that are not captured by the average energy-based noise descriptors. The study investigates the ability of IR to increase the explained variance of noise annoyance in a large socio-acoustic survey in the Swiss population as well as the explanatory power of IR in epidemiological noise effect models. To further understand which aspects of the temporal pattern of noise exposure are relevant, we also investigated the degree to which the IR-metric is associated with the self-reported perception of individuals about the intermittency of noise exposure in their home.