Short-term noise annoyance assessment in passenger compartments of high-speed trains under sudden variation

The sounds in passenger compartments of high-speed trains operating in Korea under various conditions were measured, and its evaluation method for annoyance is presented. The stationary noise was measured for trains operating on ballast, concrete, open, or tunneled tracks at different speeds. The unsteady sudden variation of sound resulting from the entrance or exit of a tunnel, or passing another train traveling in the opposite direction was also measured. The sound pressure level and sound quality metrics such as loudness, sharpness and roughness were calculated for different conditions, and their variations were compared. The short-term annoyance was evaluated for various sounds using a paired comparison method. The loudness exhibited a closer correlation to the annoyance resulting from many different noise sources in the passenger compartment for stationary sounds but was not sufficient in rating noises under sudden variation. To evaluate the annoyance caused by the unsteady sound, a parameter adopting moving average filter to reflect the rate of change in sound quality metrics was proposed. Using statistical analysis, a sound index for estimating the annoyance using independent variables was developed, and its accuracy was compared to existing psychoacoustic annoyance model proposed by Zwicker and Fastl.