title: Comparisons between physics-based, engineering, and statistical learning models for outdoor sound propagation.
abstract: Many outdoor sound propagation models exist, ranging from highly complex physics-based simulations to simplified engineering calculations, and more recently, highly flexible statistical learning methods. Several engineering and statistical learning models are evaluated by using a particular physics-based model, namely, a Crank-Nicholson parabolic equation (CNPE), as a benchmark. Narrowband transmission loss values predicted with the CNPE, based upon a simulated data set of meteorological, boundary, and source conditions, act as simulated observations. In the simulated data set sound propagation conditions span from downward refracting to upward refracting, for acoustically hard and soft boundaries, and low frequencies. Engineering models used in the comparisons include the ISO 9613-2 method, Harmonoise, and Nord2000 propagation models. Statistical learning methods used in the comparisons include bagged decision tree regression, random forest regression, boosting regression, and artificial neural network models. Computed skill scores are relative to sound propagation in a homogeneous atmosphere over a rigid ground. Overall skill scores for the engineering noise models are 0.6%, -7.1%, and 83.8% for the ISO 9613-2, Harmonoise, and Nord2000 models, respectively. Overall skill scores for the statistical learning models are 99.5%, 99.5%, 99.6%, and 99.6% for bagged decision tree, random forest, boosting, and artificial neural network regression models, respectively.
authors.affiliation: U.S. Army Cold Regions Research and Engineering Laboratory, Engineer Research and Development Center, Hanover, New Hampshire 03755-1290, USA.
authors.forename: Carl R
authors.initials: CR
authors.lastname: Hart
authors.affiliation: U.S. Army Cold Regions Research and Engineering Laboratory, Engineer Research and Development Center, Hanover, New Hampshire 03755-1290, USA.
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Reznicek
authors.affiliation: U.S. Army Cold Regions Research and Engineering Laboratory, Engineer Research and Development Center, Hanover, New Hampshire 03755-1290, USA.
authors.forename: D Keith
authors.initials: DK
authors.lastname: Wilson
authors.affiliation: Aerospace Engineering Department, United States Naval Academy, Annapolis, Maryland 21402-5042, USA.
authors.forename: Chris L
authors.initials: CL
authors.lastname: Pettit
authors.affiliation: U.S. Army Construction Engineering Research Laboratory, Engineer Research and Development Center, Champaign, Illinois 61826-9005, USA.
authors.forename: Edward T
authors.initials: ET
authors.lastname: Nykaza