Traffic noise dominates in urban environments
Traffic noise is the dominant source of acoustic and seismic noise in urban environments, according to an upcoming scientific study, with volume levels only exceeded by construction sites in isolated areas where construction activity is taking place.
In an article to be published in April 2017’s Applied Acoustics, researchers at the Engineer Research and Development Center, Cold Regions Research and Engineering Laboratory (ERDC-CRREL) in the United States compared urban and rural measurements of acoustic and seismic noise.
Their detectors spanned a broader range of frequencies than is normally the case, picking up seismic waves from 6 Hz to 1 kHz and acoustic waves from 6 Hz to 20 kHz, and found traffic noise to be the major contributor in urban areas, outside of a few peaks at specific frequencies relating to construction work.
“The urban acoustic measurements are dominated by traffic noise,” the researchers write in their article.
“The seismic signatures also are heavily influenced by traffic noise but exhibit more variation with respect to urban location due to the influence of subsurface conditions.”
In both cases, noise levels are measurably much higher in urban settings than rural areas, although the gap narrows quickly at higher frequencies, suggesting that acoustic insulation for the underbody of vehicles could be most effective by blocking the low-frequency rumble of engines and exhausts.