Acentech Inc., working with Tetra Tech, Inc., was the acoustical consultant for the design of approximately 13,000 linear ft. of noise barrier along one side of a two-track railway corridor that runs east/west between Anaheim and Yorba Linda, California. The primary concerns were twofold: to achieve adequate shielding for residents behind the barrier; to minimize increases in noise level due to reflections for residents on the railway side of the barrier.

Acentech modeled the acoustical performance of the soundwall to ascertain the required barrier length and height. We also analyzed the potential impacts of adding a third track. In 2001 we prepared a noise engineering report that documented existing and future noise levels north and south of the railway corridor and detailed the locations, heights, and materials to reduce community noise to the City of Anaheim requirments. Recommended wall heights were between 4 meters and 8 meters. We also performed scale model testing of a 1/2-scale soundwall that local residents were invited to witness.

The soundwall construction was completed in 2006. Acentech performed acoustical performance testing of the completed wall using the indirect method described in ANSI S12.8-1998. The measured noise insertion loss (noise reduction) of the soundwall was between 15 dBA and 22 dBA; exceeding the expectations of the City.