NOISE PROPAGATION PATHS FOR HIGHWAY NOISE BARRIERS

There are three potential paths for noise propagation from the traffic side of a highway noise barrier to the other side of the barrier; 1) transmission through the barrier, 2) diffraction at the edges of the barrier, and 3) scattering from atmospheric turbulence above the barrier. A wood barrier was built. To separate propagation paths, measurements were conducted with an array of microphones steered toward the surface of the barrier, to the top edge of the barrier, and above the barrier. Also, measurements were made with the ground on the receiver side of the barrier partially covered with reflecting and absorptive surfaces. Finally, the vibration response of the barrier was measured and used to estimate transmission through the barrier. Results from these measurements are discussed. (A) For the covering abstract see ITRD E113232.