The impact of including diffraction when predicting the effect of listener environment on the perceived loudness of outdoor sonic booms

The human impact of sonic booms varies with listening environment. Given the incident sonic boom waveform, the specular field around a realistic geometry has been predicted via a C++ implementation of image source method (ISM) tailored to this outdoor application. This work explores the necessity of including the diffracted field when predicting time series and perceived loudness (PLdB), both in and out of the shadow zone. The impulsive nature of the excitation, and the sensitivity of the PLdB to temporal details, constrains appropriate diffraction modeling techniques to those capable of time domain accuracy. Uniform Theory of Diffraction (UTD) and Biot Tolstoy Medwin (BTM) models are considered, exploring the benefits and challenges of each approach, particularly with regards to scalability and bandwidth. The importance of accurately predicting diffraction for this application is evaluated through comparison with booms recorded around a building corresponding to the simulated geometry.