Room acoustic and electroacoustic analysis. Design of Swedish courtrooms.

Abstract

Today, many old courtrooms are renovated in order to satisfy new acoustical requirements derived from recent modernization of trials. The acoustical design in courtrooms has become complex, as trials are recorded and standard on sound quality raised. To be able to meet the quality set by the court system when recording trials, microphones and a certain acoustic environment is required. The environments in courtrooms are characterized by short reverberation times resulting in difficulty for the audience to hear and poor quality recordings. It is then necessary to include loudspeakers. It is complex to design for both humans and recorders as they interpret sound differently. This thesis analyses a courtroom and its speech intelligibility by utilizing the measurement program WinMLS and the information achieved from subjective listening tests. Further, a model that optimises the acoustics of the room by utilizing CATT-Acoustics based on the analysis is derived.