Geophysical Detection Programs, Sandia National Laboratories, 1515 Eubank Southeast, MS 0404, Albuquerque, New Mexico 87123, USA.
Advanced Technologies Division, Nevada National Security Site, P.O. Box 98521, Las Vegas, Nevada 89193-8521, USA.
J Acoust Soc Am. 2021 Mar;149(3):1796. doi: 10.1121/10.0003777.
While studies of urban acoustics are typically restricted to the audio range, anthropogenic activity also generates infrasound (<20 Hz, roughly at the lower end of the range of human hearing). Shutdowns related to the COVID-19 pandemic unintentionally created ideal conditions for the study of urban infrasound and low frequency audio (20-500 Hz), as closures reduced human-generated ambient noise, while natural signals remained relatively unaffected. An array of infrasound sensors deployed in Las Vegas, NV, provides data for a case study in monitoring human activity during the pandemic through urban acoustics. The array records a sharp decline in acoustic power following the temporary shutdown of businesses deemed nonessential by the state of Nevada. This decline varies spatially across the array, with stations close to McCarran International Airport generally recording the greatest declines in acoustic power. Further, declines in acoustic power fluctuate with the time of day. As only signals associated with anthropogenic activity are expected to decline, this gives a rough indication of periodicities in urban acoustics throughout Las Vegas. The results of this study reflect the city's response to the pandemic and suggest spatiotemporal trends in acoustics outside of shutdowns.
虽然城市声学研究通常仅限于音频范围，但人为活动也会产生次声（<20 Hz，大致在人类听力范围的低端）。与 COVID-19 大流行相关的关闭无意中为城市次声和低频音频（20-500 Hz）的研究创造了理想的条件，因为关闭减少了人为产生的环境噪声，而自然信号相对不受影响。在内华达州拉斯维加斯部署的一组次声传感器提供了一个案例研究的数据，该研究通过城市声学监测大流行期间的人类活动。该阵列记录到在该州认定为非必要的企业临时关闭后，声能急剧下降。这种下降在阵列中存在空间差异，靠近麦卡伦国际机场的站点通常记录到声能下降最大。此外，声能的下降随时间而波动。由于预计只有与人为活动相关的信号会下降，这大致反映了拉斯维加斯整个城市声学的周期性。这项研究的结果反映了城市对大流行的反应，并表明了关闭之外的声学的时空趋势。
