Cumulative sound exposure levels—Insights from seismic survey measurements

Abstract

The weighted cumulative sound exposure level from man-made noise sources is often recommended as a method of measuring possible injury to marine life hearing. However, the behavior of this metric over large areas and its evolution in time is poorly documented in the scientific literature. Similarly, the differences in sound exposure levels as a result of changing the frequency weighting functions are only vaguely discussed. In this presentation, we provide insights into the behavior of the SEL metric based on measurements of several seismic surveys and simulations of seismic vessels passing a recording location. Based on the real-world measurements, we show how the range at which the surveys exceed the regulatory thresholds is highly dependent on the weighting functions and threshold values.