Enhancement of acoustic environment with regard to speech privacy and annoyance in passenger cars of high-speed trains

Abstract

This study aims to determine the optimal acoustic environment in passenger cars of high-speed trains considering speech privacy and noise annoyance. Listening tests were conducted to examine the relationship between speech privacy and noise annoyance. In the first session, speech intelligibility was evaluated using Korean sentences with respect to background noise and speech sources. In the second session, participants were asked to read articles in a passenger car with conversations and interior noise and then to assess the speech privacy and noise annoyance. The auditory tests were performed for varying background noise levels and signal-to-noise (S/N) ratios. Using the results, an optimal level of interior noise, taking speech privacy and annoyance into consideration, was suggested to improve the acoustic comfort in passenger cars of high speed trains.