Analysis and acoustical modeling of transit noise reflections to residential locations

Abstract

As development progresses in urban areas, it is common that new projects are developed adjacent to existing public transportation systems. Varying in dimensions and facade materials, these new developments introduce new surfaces off of which sound can reflect to locations previously not impacted. The acoustical ramifications of the facades of new developments are often ignored and can create reflections to residential locations that are additive to the direct sound of the transit system. These reflections can be subjectively regarded by nearby residents as bothersome or intrusive. We have studied one such case of reflected transit noise adversely impacting nearby residents. We measured short duration sound pressure levels (Lps) of the transit activity near the affected residential locations and created a three-dimensional sound propagation model to better understand the impact of transit noise reflections off of two nearby residential developments, comparing the results of our study with Federal Transit Authority Guidelines.