Determination of exhaust sound pressure levels emitted by road vehicles in Sri Lanka

Abstract

Vehicle noise is the most widespread source of noise pollution in Sri Lanka. Exhaust noise is a major component of total noise generated by a vehicle. There is no regulation enforced in Sri Lanka to control vehicle exhaust noise. Therefore, this study was done with the purpose of addressing this issue. Exhaust sound pressure levels (ESPLs) of a sample of stationary vehicles were measured in accordance with ISO 5130:2007 along with influencing factors of ESPL. The principle findings revealed that ESPLs of automatic transmission, hybrid and petrol engine vehicles are lower than those of other vehicles. ESPLs of several stationary road vehicles exceeded the maximum permissible noise limits specified in international regulations. Finally, baseline data were established using the results obtained from statistical analysis, to introduce regulations to Sri Lanka, so that the vehicle owners will have to take steps to maintain the ESPLs of their vehicles at appropriate levels.