Annoyance and activity disturbance induced by high-speed railway and conventional railway noise: a contrastive case study

Abstract

Doc number: 12

Abstract

Background: High-speed railway (HR, Electrified railway with service speed above 200 km/h.) noise and conventional railway (CR, Electrified railway with service speed under 200 km/h.) noise are different in both time and frequency domain. There is an urgent need to study the influence of HR noise and consequently, develop appropriate noise evaluation index and limits for the total railway noise including HR and CR noise.

Methods: Based on binaural recording of HR and CR noises in a approximate semi-free field, noise annoyance and activity disturbance induced by maximal train pass-by events in China were investigated through laboratory subjective evaluation. 80 students within recruited 102 students, 40 males and 40 females, 23.9 ± 2.1 years old, were finally selected as the subjects. After receiving noise stimulus via headphone of a binaural audio playback system, subjects were asked to express the annoyance or activity disturbance due to railway noise at a 0-100 numerical scale.

Results: The results show that with the same annoyance rating (A ) or activity disturbance rating (D ), the A-weighted equivalent sound pressure level (L _Aeq ) of CR noise is approximately 7 dB higher than that of HR noise. Linear regression analysis between some acoustical parameters and A (or D ) suggests that the coefficient of determination (R² ) is higher with the instantaneous fast A-weighted sound pressure level (L _AFmax ) than that with L _Aeq . A combined acoustical parameter, L _HC = 1.74L _AFmax + 0.008L _AFmax (L _p -L _Aeq ), where L _p is the sound pressure level, was derived consequently, which could better evaluate the total railway noise, including HR and CR noise. More importantly, with a given L _HC , the noise annoyance of HR and CR noise is the same.

Conclusions: Among various acoustical parameters including L _HC and L _Aeq , A and D have the highest correlation with L _HC . L _HC has been proved to be an appropriate index to evaluate the total railway noise, including both HR and CR. However, it should be pointed out that this study provides suggestive evidence, rather than a final proof. Further study is expected to elucidate conclusions above by additional measurements.