Perceptual evaluation of violin radiation characteristics in a wave field synthesis system

A method to synthesize the sound radiation characteristics of musical instruments in a wave field synthesis (WFS) system is proposed and tested. Radiation patterns of a violin are measured with a circular microphone array which consists of 128 pressure receivers. For each critical frequency band one exemplary radiation pattern is decomposed to circular harmonics of order 0 to 64. So the radiation characteristic of the violin is represented by 25 complex radiation patterns. On the reproduction side, these circular harmonics are approximated by 128 densely spaced monopoles by means of 128 broadband impulses. An anechoic violin recording is convolved with these impulses, yielding 128 filtered versions of the recording. These are then synthesized as 128 monopole sources in a WFS system and compared to a virtual monopole playing the unfiltered recording. The study participants perceive the tone color of the recreated virtual violin as being dependent on the listening position and report that the two source types have a different ‘presence’. The test persons rate the virtual violin as less natural, sometimes remarking that the filtering is audible at high frequencies. Further studies with a denser spacing of the virtual monopoles and a presentation in an anechoic room are planned