Plenary Lecture
Further Developments in the Emulation of Non-Linear Acoustic Systems
Professor Lamberto Tronchin
DN - CIARM
University of Bologna
Italy
E-mail: Lamberto.tronchin@unibo.it
Abstract: It is well-known in acoustics that the emulation of the acoustics of a theatre or an auditorium could be obtained by means of convolution between dry signal and a properly-measured impulse response. However, a considerable number of audio devices (as valve amplifier or musical instruments) could definitely not be considered as linear and time-invariant systems. By using Hammerstein or Wiener series it is possible to represent the input-output relationship of nonlinear systems. These two methods could be generalised using Volterra model. It uses a set of impulse responses to describe the system and not only one as before. By an enhanced impulse response measurement method it is possible to obtain this set of impulses and then with Volterra series it would be possible to have the output of the audio system driven by any input. A special numerical tool has been developed to recreate the system behaviour by using this method. This method has been recently further developed, taking into consideration the effects of amplitude during the emulation of the device and the proper determination of the most suitable set of distortion considering the RMS value of the “dry signal” to be used for the emulation. In the lecture, the most remarkable results will be presented.
Brief Biography of the Speaker: Dr Lamberto Tronchin is Associate Professor in Environmental Physics from the University of Bologna and is recognised internationally as a leading authority on the subject of sound and acoustics. A pianist himself, with a diploma in piano from the Conservatory of Reggio Emilia, Dr Tronchin's principal area of research has been musical acoustics, room acoustics and signal processing. He is Associate Editor of the Journal of AES, and the author of more than 200 papers and was Chair of the Musical Acoustics Group of the Italian Association of Acoustics from 2000 to 2008. Dr Tronchin is a member of the Scientific Committee of the CIARM, the Inter- University Centre of Acoustics and Musical research, has chaired sessions of architectural and musical acoustics during several international symposiums, been a referee for a number of International journals and is Chair of Organising and Scientific Committees of IACMA (International Advanced Course on Musical Acoustics).
He was a visiting researcher at the University of Kobe in Japan, a visiting professor at the University of Graz in Austria and Special honored International Guest at the International Workshop, ‘Analysis, Synthesis and Perception of Music Signals', at Jadavpur University of Kolkata, India in 2005. He has chaired the International Advanced Course on Musical Acoustics (IACMA), organised with the European Association of Acoustics, which was held in Bologna, in 2005. Since 2008 he gave plenary lectures at International Congresses on Acoustics in Vancouver, Prague, Bucharest, Santander, Kos, Malta, Paris, Cambridge (UK), Salerno, Geneve. He designed theatres and other buildings, as acoustic consultant, in collaboration with several Architects, among them Richard Meier and Paolo Portoghesi.