Listening Difficulty of Public Announcement at Subway Platform with Long Reverberation Time

The subway platform is a unique spaces where the reverberation time (RT) is extended depending on the distance from the sound source. Moreover, various noise sources is being occurred at the subway platform such as the train approaching noise, crowd noise, and so on. The purpose of this study is to determine which factor affects the listening difficulty of announcement through listening test based on the acoustical data from on-site measurements. The results of listening test show that the difference according to the types of noise sources, S/N ratio, and RT was found to be significant. In particular, the difference between RT of 2.2 s and 3.6 s showed the largest difference of up to 65.1 % in listening difficulty rating. In addition, the influence of noise type on listening difficulty rating was found in the condition of RT 2.2 s, but not in RT 3.6 s. Announcement combined with the crowd noise was to be the most difficult to listen to among noise types in the better acoustical condition.