OCTAVE BAND ANALYSIS OF CAR NOISE EMISSIONS AT DIFFERENT SPEEDS AND ON DIFFERENT PAVEMENTS

Noise from cars is one of the main sources of harmful pollution. In the presented paper, an octave frequency band analysis is conducted according to standard methods of external and internal noise measurement. Experiments at different speeds, with three types of cars—conventional gasoline (GV), hybrid (HEV) and pure electric (BEV)— were carried out on two types of pavement—damaged coarse-grained and smooth finegrained asphalt. The results show variations in external and internal noise levels vs. speed in different octave bands. At each speed, a spectral analysis was done. The diagrams with results show changes in noise level vs. speed and the positions of noise maximums. Regression models for the octave spectrum at different speeds and pavements are developed.