Model-based sound synthesis of the guqin

Abstract

This paper presents a model-based sound synthesis algorithm for the Chinese plucked string instrument called the guqin. The instrument is fretless, which enables smooth pitch glides from one note to another. A version of the digital waveguide synthesis approach is used, where the string length is time-varying and its energy is scaled properly. A body model filter is placed in cascade with the string model. Flageolet tones are synthesized with the so-called ripple filter structure, which is an FIR comb filter in the delay line of a digital waveguide model. In addition, signal analysis of recorded guqin tones is presented. Friction noise produced by gliding the finger across the soundboard has a harmonic structure and is proportional to the gliding speed. For pressed tones, one end of a vibrating string is terminated either by the nail of the thumb or a fingertip. The tones terminated with a fingertip decay faster than those terminated with a thumb. Guqin tones are slightly inharmonic and they exhibit phantom partials. The synthesis model takes into account these characteristic features of the instrument and is able to reproduce them. The synthesis model will be used for rule based synthesis of guqin music.

Some Remarks on the Acoustics of the Piano

“…Our discussion to this point has been qualitative -to go further we must estimate the various effect quantitatively, and that requires computer modeling. As examples of such modeling work we will describe two recent projects by the author; however, many other workers are active in this field and we refer the interested reader to several recent publications for descriptions and references to this work (Bader 2005;Bensa et al 2005;Deveaux et al 2003;Penttinen et al 2006).…”

Analysis of handling noises on wound strings

“…4 However, based on the knowledge obtained in this article, a more sophisticated physics-based model for synthesizing wound string contact noises will be presented in an upcoming article on slide guitar synthesis. 7 There, the contact noise between a wound string and the slide tube is synthesized with a noise pulse train-based parametric model.…”

“…This effect was found already earlier in a recent study. 4 Also, the amplitude of the handling noise increases with slide velocity. It can be seen in Fig.…”

The influence of cellist's postural movements on their musical expressivity

“…Ces techniques permettent une modélisation relativement fine des paramètres de contrôle de l'instrument, ainsi qu'un rendu expressif accru lors du contrôle des algorithmes de synthèse sonore. On les retrouve appliquées pour les instruments à son entretenu, tels que le violon [Demoucron 2007, Maestre 2009], l'alto [Poepel 2004], le guqin (vieille cithare chinoise) [Penttinen 2006], et le sho (instrument à vent africain) [Hikichi 2004]. …”