Comparison Of High-speed Railway And Conventional Railway Noise

The time domain, frequency spectrum and the acoustic field distribution of the high-speed railway (HSR) noise are different from those of conventional railway (CR) noise. For this reason, based on the noise sample acquired at actual railway, comparative study of the noise characteristics and subjective response of HSR and CR noise was carried out.As the results shown, the actual noise duration (Td) of HSR noise at each test point was 6.1-13.5 seconds, and Td of CR noise was 16.0-25.7 seconds. It was indicated that SHR noise was more sudden than CR noise. Due to the high speed, the sound wave Doppler effect on both sides of HSR was quite obvious. With the distance between the CR and test point increasing, the SPL of noise decreased. However, the SPL of the noise tested at distance of 30-50 m between the HSR and test point was highest, which might be due to the sound insulation of the viaduct surface and the safety bars on both sides.The subjective evaluation experimental results showed that, with the gradual reduction of the railway noise, the annoyance and subjective interference were also decreased gradually. With the same LAeq. the annoyance and subjective interference of the HSR were higher than those of the CR. Compared with LAeq, the other indexes of the two kinds of railway noise, including LAFmax, LASmax, Lc, Lp and LAeq+0.009 LAeq(Lp-LAeq), got better correlation with the evaluation results. And the Pearson correlation between the last one and evaluation results was the highest, which exceeded 0.974.If noise emission standards were needed for the HSR, it was proposed that 63dBA and 53dBA were reasonable LAeq limits for day and night, respectively. If uniform noise emission standards of the HSR and the CR were needed, LASmax was recommended to be the evaluation index. In addition, it was suggested that 80dBA and 70dBA were reasonable LAeq limits for day and night, respectively.