Acoustic design of transit stations

The acoustical environment in transit stations is being given increasing attention, particularly in national codes and client standards which now include requirements for intelligibility of voice alarm systems. This differs from the past where fewer loudspeakers with greater sound pressure output levels could be used to fulfill overall sound level criteria, with little consideration for alarm intelligibility. Room acoustics in stations is being considered using techniques previously reserved for performance venues to achieve these intelligibility criteria. In addition, noise from tunnel ventilation systems for exhaust and emergency smoke extract is a growing concern that requires attention to meet strict criteria in often constrained spatial conditions and demanding environmental requirements. This paper presents a review of the key challenges and best practices in acoustic design of transit stations.