DAVID A. BIES AND COLIN H. HANSEN

David A. Bies is now retired having served as a Reader and then Visiting Research Fellow at the University of Adelaide's School of Mechanical Engineering. He is an expert and widely published acoustics physicist who has also worked as a senior consultant in industry. Colin H. Hansen is Professor and Head of the School of Mechanical Engineering at the University of Adelaide. With a wealth of experience in consulting, research and teaching in acoustics, he has authored numerous books, journal articles and conference proceedings on the topic.