Electroacoustic modeling of speech intelligibility for a new road tunnel

Abstract

This paper presents the process of electroacoustic design and modeling for tunnel public address (PA) system for the North East Link (NEL) road tunnel in Melbourne. The tunnel includes over 6km of twin-bore tunnels, with varying cross-sections along its length. The different tunnel spaces addressed in the design include mainline tunnel bores, interchanges, ramps, as well as pedestrian cross-passages and egress passages. This paper outlines how large data sets from CAD models were managed using a new automation method (Grasshopper 3D) throughout the design process to produce and maintain detailed electroacoustic modeling in Odeon software. In particular, this paper explores new and novel modeling methods adopted to address design constraints and to achieve a PA system capable of producing adequate speech intelligibility for emergency evacuation within very challenging acoustic environments.