Past Research on Sound Propagation through Forests

Abstract

This report reviews past scientific research to determine whether forests have any noise reduction effects for blast noise from artillery training or explosions. Unfortunately, there has been very little relevant work that would contribute to answering this question. For military noise sources, the main frequencies of interest are below 100 Hz. Most of the past investigations have been done at high frequencies using low-amplitude continuous wave noise sources rather than high-amplitude impulsive sources. For these reasons, additional measurements will be needed to determine the effect of forests on artillery and blast noise. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.

Perceived Occurrences of Soundscape Influencing Pleasantness in Urban Forests: A Comparison of Broad-Leaved and Coniferous Forests

“…According to the theory of soundscape ecology and psychophysics [3,6,26,33,43,44], soundscape in urban forests is the sound energy produced by the superposition and mixing of geophony, biophony, and anthrophony sound sources [27]. We consider the soundscape in urban forests to also be affected by the uncertain occurrences of soundscape.…”

Auditory Distance Estimation in an Open Space

“…At intermediate distances, up to approximately 200-300 m, and at low frequencies the loss of sound energy due to atmospheric absorption by a laminar (not turbulent) medium is usually small (less than 1 dB) and can be neglected for practical purposes [46]. However, at large distances and high frequencies energy loss due to atmospheric absorption can be quite large and exceed the loss caused by a three-dimensional spread of energy.…”

Effects of Forest on Blast Noise

“…References were assessed for scientific accuracy and relevancy (Albert 2004). During FY01 an existing data set also was investigated, the so-called Norway trials, for low-frequency blast noise propagation through forests ).…”