Paper Archive

This paper investigates the use of a physical model template database as the parameter basis for a MPEG-4 Structured Audio (MP4-SA) codec. During analysis, the codec attempts to match the closest corresponding instrument in the database. In this paper, we emphasize the mechanism enabling this match. We give an overview of the final front end, including the pitch detection stage, and remaining problems are discussed. A draft implementation, written in the Python language is described.

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The recent trend towards the virtual in music synthesis has lead to the inevitable decline of the physical, inserting what might be described as a ‘veil of tactile paralysis’ between the musician and the sound source. The addition of tactile and gestural interfaces to electronic musical instruments offers the possibility of moving some way towards reversing this trend. This paper describes a new computer based musical instrument, known as Cymatic, which offers gestural control as well as tactile and proprioceptive feedback via a force feedback joystick and a tactile feedback mouse. Cymatic makes use of a mass/spring physical modelling paradigm to model multi-dimensional, interconnectable resonating structures that can be played in real-time with various excitation methods. It therefore restores to a degree the musician’s sense of working with a true physical instrument in the natural world. Cymatic has been used in a public performance of a specially composed work, which is described.

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This paper describes an experimental research tool for block-based physical modeling and DSP computation. The goals of the development have been high abstraction level and flexibility in model specification without compromising computational efficiency in real-time simulation and application execution. To achieve both goals, the Lisp language is used for symbolic manipulation of computational block structures and C language for compilation of efficient executables. The primary motivation for this tool has been to enable flexible generation of physical models where twodirectional interaction between elements is needed. A particular feature of the system is support for mixed modeling by combining digital waveguides, finite difference schemes, wave digital filters, as well as traditional block-based DSP algorithms.

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When an unsmooth flexible tube rotates, rich tones are produced. We propose a physical model that simulates this behavior. The tube is modeled as an open-ended organ pipe blown by an air stream pumped by a rotationally induced pressure which follows Bernoulli’s principle.

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The success recently encountered by physically-based modeling (or model-based approaches) for music should not mask the deep challenges that remain in this area. This article first proposes an overview of the various goals that researchers and musicians, respectively operating from scientific and end-user perspectives, may pursue. Among these goals, those recently proposed or particularly critical for the coming years of research are highlighted. The article then introduces ten criteria that summarize the main features an optimal physically-based modeling scheme or language should present. With respect to these, it proposes an evaluation of the major approaches to physically-based modeling. Key words: goals of the physically-based approach to sound synthesis and music creation, languages and schemes, enduser needs, perception, evaluation criteria, bibliographic overview.

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In the context of Computer Music, physical modeling is usually dedicated to the modeling of sound sources or physical instruments. This paper presents an innovative use of physical modeling in order to model and synthesize complex auditory effects such as collective acoustic phenomena producing metabolic emergent auditory organizations. As a case study, we chose the ‘dune effect’, which in open nature leads both to visual and auditory effects. The article introduces two particle physical models, able to collaborate. The first is dedicated the synthesis of spatial (or visual) dynamics effects of moving sand dunes. The second i s dedicated to the rendering of acoustical dynamics of “sounding sands”. Altogether, they lead to a multisensorial simulation of sand in dune. Keywords: auditory effects, metabolic effects, emergence, sonification process, sounding sands,

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A new estimation technique is proposed which computes the control parameters of a physical model of a trumpet in order to simulate a recording of a real instrument. First, the physical constraints of the instrument and the prior knowledge about how a player controls a trumpet are described. This is taken into account during the design of the data set and guarantees that these constraints are respected. Then, an estimation procedure minimizes two perceptual similarity criteria in function of the control parameters. The first criterium expresses the difference of the spectral envelopes and the second one the difference in fundamental frequency. An optimization technique is proposed that yields an optimal solution for the fundamental frequency, and a conditional suboptimal solution for the spectral envelope. A robust implementation of the technique was developed for which it is shown that the estimated parameters are unique and that the optimization does not suffer from local minima.

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Current physics-based synthesis techniques tend to synthesize the interaction between different functional elements of a sound generator by treating it as a single system. However, when dealing with the physical modeling of complex sound generators this choice raises questions about the resulting flexibility of the adopted synthesis strategy. One way to overcome this problem is to approach it by individually synthesizing and discretizing the objects that contribute to the generation of sounds. In this paper we address the problem of how to automatize the process of physically modeling the interaction between objects, and how to make it dynamical. We will show that this can be done through the automatic definition and implementation of a topology model that adapts to the contact and proximity conditions between the considered objects.

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The Functional Transformation Method (FTM) is a recently introduced method for sound synthesis by physical modeling. Based on integral transformations, it provides a parallel system description for any linear physical model, usually described by a set of partial differential equations. Such parallel descriptions can be directly implemented by a set of recursive systems in full rate. In this PSfrag replacem paper we present a new and very ef£cient method for this implementation which bene£ts from the spectral decomposition of the system. All recursive systems are working at a subsampled rate and are summed up by the application of a polyphase £lterbank. Performance measurements on a real time implementation show, that a ¤exible and ef£cient realization is achieved. Compared to the direct implementation it is over nine times faster at the cost of nine milliseconds of delay and even faster with more delay.

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This paper describes the structure and potential of a real-time sound model of “rolling”. The work has it’s background and motivation in the ecological approach of psychoacoustics. Scope of interest is the efficient and clear (possibly exaggerated) acoustic expression, cartoonification, of certain ecological attributes rather than realistic simulations for their own sake. To this end, different techniques of sound generation are combined in a hybrid hierarchical structure. A physics-based algorithm (section 2) of impact-interaction at the audio-core is surrounded by higher-level structures that explicitely model macroscopic characteristics (section 5). Another connecting audio-level algorithm, the “rolling-filter”, reduces the (3-dimensional) geometry of the rolling-contact to the one dimension of the impactinteraction-model (section 3).

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