Download A multirate, finite-width, bow-string interaction model In this paper we propose an efficient method to model the amount of bow hair in contact with the string in a physical model of a bowed string instrument.
Download Extended performance techniques for a virtual instrument In this paper we explore extended techniques for a physical model of a bowed string instrument controlled using the metasaxophone.
Download Model-based synthesis and transformation of voiced sounds In this work a glottal model loosely based on the Ishizaka and Flanagan model is proposed, where the number of parameters is drastically reduced. First, the glottal excitation waveform is estimated, together with the vocal tract filter parameters, using inverse filtering techniques. Then the estimated waveform is used in order to identify the nonlinear glottal model, represented by a closedloop configuration of two blocks: a second order resonant filter, tuned with respect to the signal pitch, and a regressor-based functional, whose coefficients are estimated via nonlinear identification techniques. The results show that an accurate identification of real data can be achieved with less than regressors of the nonlinear functional, and that an intuitive control of fundamental features, such as pitch and intensity, is allowed by acting on the physically informed parameters of the model. 10
Download Flexible software framework for modal synthesis Modal synthesis is an important area of physical modeling whose exploration in the past has been held back by a large number of control parameters, the scarcity of generalpurpose design tools and the difficulty of obtaining the computational power required for real-time synthesis. This paper presents an overview of a flexible software framework facilitating the design and control of instruments based on modal synthesis. The framework is designed as a hierarchy of polymorphic synthesis objects, representing modal structures of various complexity. As a method of generalizing all interactions among the elements of a modal system, an abstract notion of energy is introduced, and a set of energy transfer functions is provided. Such abstraction leads to a design where the dynamics of interactions can be largely separated from the specifics of particular modal structures, yielding an easily configurable and expandable system. A real-time version of the framework has been implemented as a set of C++ classes along with an integrating shell and a GUI, and is currently being used to design and play modal instruments, as well as to survey fundamental properties of various modal algorithms.
Download Using the waveguide mesh in modelling 3D resonators Most of the results found by several researchers, during these years, in physical modelling of two dimensional (2D) resonators by means of waveguide meshes, extend without too much difficulty to the three dimensional (3D) case. Important parameters such as the dispersion error, the spatial bandwidth, and the sampling efficiency, which characterize the behavior and the performance of a waveguide mesh, can be reformulated in the 3D case, giving the possibility to design mesh geometries supported by a consistent theory. A comparison between different geometries can be carried out in a theoretical context. Here, we emphasize the use of the waveguide meshes as efficient tools for the analysis of resonances in 3D resonators of various shapes. For this purpose, several mesh geometries have been implemented into an application running on a PC, provided with a graphical interface that allows an easy input of the parameters and a simple observation of the consequent system evolution and the output data. This application is especially expected to give information on the modes resonating in generic 3D shapes, where a theoretical prediction of the modal frequencies is hard to do.
Download Estimating the plucking point on a guitar string This paper presents a frequency-domain technique for estimating the plucking point on a guitar string from an acoustically recorded signal. It also includes an original method for detecting the fingering point, based on the plucking point information.
Download 3D graphics tools for sound collections Most of the current tools for working with sound work on single soundfiles, use 2D graphics and offer limited interaction to the user. In this paper we describe a set of tools for working with collections of sounds that are based on interactive 3D graphics. These tools form two families: sound analysis visualization displays and model-based controllers for sound synthesis algorithms. We describe the general techniques we have used to develop these tools and give specific case studies from each family. Several collections of sounds were used for development and evaluation. These are: a set of musical instrument tones, a set of sound effects, a set of FM radio audio clips belonging to several music genres, and a set of mp3 rock song snippets.
Download Modeling high-frequency modes of complex resonators using a waveguide mesh This paper describes the use of a digital waveguide mesh which provides certain desirable components of the frequency response of the body of an instrument. An application for the violin is illustrated, showing that meshes can be designed to have a modal distribution which is psychoacoustically equivalent to the resonances of the violin body at high frequencies.
Download Digital sound synthesis, acoustics and perception: a rich intersection The early years of digital sound synthesis were filled with promise following Max Mathews’ publication in 1963 of his pioneering work at Bell Telephone Laboratories [1]. The digital control of loudspeakers allowed for the production of any conceivable sound given the correct sequence of numbers (samples). Producing the correct sequence of numbers, however, turned out to be a formidable task. Acoustics and psychoacoustics, the first a well-developed field of knowledge and the second less so, did not provide information at the level of detail required to simulate even the simplest sound of an acoustic instrument. The enormous potential of digital synthesis counterpoised with an enormous knowledge deficit were the initial conditions for interdisciplinary research that continues to this day. Discoveries have been made and insights gained that are of consequence in the general field of digital audio.