An attempt to decrease the noise pollution of urban busses using a new exhaust silencer

Abstract

The paper presents an attempt to reduce the noise pollution of urban buses through the investigation of the efficiency of a new exhaust silencer, comparing to the original one. First, the sound pressure levels (SPL) and sound spectra were measured outside and inside the stationary bus, at two engine revolution speeds, with and without original exhaust silencer. The data show a higher efficiency of the screens around the engine comparing to the original silencer. An experimental prototype was designed and built. The noise measurements made with the prototype silencer fitted on the bus show a tendency of decreasing the sound pressure levels.