Stevens perceived levels of common impulsive noises, sonic booms, and sonic thumps Free

NASA’s X-59 Quiet Supersonic Technology low boom flight demonstrator aircraft is being designed to produce a shaped sonic thump of 75 dB Perceived Level (PL) at the ground. The PL metric was chosen because it correlates well with human perception of sonic booms both outdoors and indoors. Members of the public often ask how loud 75 dB PL is. To communicate this level in terms of more familiar sounds, a PL reference scale was developed. Common impulsive sounds were recorded, and their PLs were computed. Some of the various impulsive sounds include distant thunder, basketball bounces, and car door slams (79, 81, and 89 dB PL, respectively). Concorde’s 105 dB PL traditional N-wave sonic boom is also included in the reference scale. Additionally, the impulsive sounds’ energy spectral densities and sone spectra are compared to that of a simulated X-59 ground waveform.