Case study: Acoustic considerations, modelling, and auralization for large scale acoustic sculptures

Abstract

This paper summarizes the research, measurements, observations, and modelling undertaken during the acoustic design of a sonic sculpture called Tower of Voices, part of the Flight 93 National Memorial in Stoystown, PA. The Tower of Voices is a 93 foot tall concrete tower featuring 40 large-scale wind chimes ranging in length from 5 to 10 feet. Due to the unprecedented nature of this project, the acoustic behavior of the chimes and interaction with the tower were the primary focus to achieve the goals of the client and designer for the soundscape visitor experience. Chime prototype mockups were undertaken to measure, record and observe sound propagation from the chimes, including the effects of different striker weights, damping materials, impact velocities, and strike locations. Acoustic modeling was utilized to assess the effect of tower shaping on the acoustic experience at various locations around the tower. An auralization was then prepared and presented in the Arup SoundLab to assist with design decisions regarding chime loudness and tower shaping. This project process of mockups, measurements, modelling, and auralization is described herein, along with a general recommended framework which can be applied to the acoustic design of large scale acoustic sculptures of many types.