Abstract
Here is presented the noise abatement devices, named noise-reducer, which are absorptive devices and mounted at the top of highway noisebarriers. The noise-reducers are developed for the noise mitigation strategy against recent increase in noise pollution problems at residential areas around highways. Scale model and full scale model experiments are carried out in order to specify the form, the size and the structure. Results of field tests at actual highways show that the insertion loss due to the application of the noise-reducer is 2dB to 3dB for road traffic noise.
