Download A Strategy for the Modular Implementation of Physics-Based Models For reasons of practical handling as well as optimization of the processes of development and implementation, it is desirable to realize realtime models of sound emitting physical processes in a modular fashion that reflects an intuitively understandable structure of the underlying scenario. At the same time, in discrete– time algorithms based on physical descriptions, the occurance of non–computable instantaneous feedback loops has to be avoided. The latter obstacle prohibits the naive cross-connection of input– output signal processing blocks. The following paper presents an approach to gain modularity in the implementation of physicsbased models, while preventing non–computable loops, that can be applied to a wide class of systems. The strategy has been realized pratically in the development of realtime sound models in the course of the Sounding Object [1] European research project.
Download Digital Sound Synthesis of Brass Instruments by Physical Modeling The Functional Transformation Method (FTM) is an established method for sound synthesis by physical modeling, which has proven its feasibility so far by the application to strings and membranes. Based on integral transformations, it provides a discrete solution for continuous physical problems given in form of initialboundary-value problems. This paper extends the range of applications of the FTM to brass instruments. A full continuous physical model of the instrument, consisting of an air column, a mouthpiece and the player’s lips is introduced and solved in the discrete domain. It is shown, that the FTM is a suitable method also for sound synthesis of brass instruments.
Download Recent Advances in Physical Modeling with K- and W-Techniques Physical (or physics-based) modeling of musical instruments is one of the main research fields in computer music. A basic question, with increasing research interest recently, is to understand how different discrete-time modeling paradigms are interrelated and can be combined, whereby wave modeling with wave quantities (W-methods) and Kirchhoff quantities (K-methods) can be understood in the same theoretical framework. This paper presents recent results from the HUT Sound Source Modeling group, both in the form of theoretical discussions and by examples of Kvs. W-modeling in sound synthesis of musical instruments.
Download Computational Real-Time Sound Simulation of Rain Real time sound synthesis in computer games using physical modeling is an area of great potential. To date, most sounds are prerecorded to match a certain event. Instead, by using a model to describe the sound producing event, a number of problems encountered when using pre-recorded sounds can be avoided. This paper deals with the application of physical modeling to the sound synthesis of rainfall. The implementation of a real-time simulation and a graphics interface allowing an interactive control of rainfall sound are discussed.
Download Sonification of the Fission Model as an Event Generation System I am proposing an event generation system for sonification purposes, where a simplified chain reaction model known as nuclear fission in physics is used. The basic background of the fission model, mapping of parameters as sonic entities and technical aspects of the realization procedure are presented.
Download Acoustical Simulations of the Human Vocal Tract Using the 1D and 2D Digital Waveguide Software Model This paper details software under development that uses the digital waveguide physical model to represent the sound creation mechanism and environment associated with the production of speech, specifically the human vocal tract. Focus is directed towards a comparison between the existing 1D waveguide method, on which several studies have already been conducted, and the developing 2D waveguide mesh method. The construction of the two models and the application of the tract geometry is examined, in addition, the inclusion of dynamic articulatory variations to increase the ability of such systems to create natural sounding speech is discussed. Results obtained from each suggest that the 2D model is capable of producing similarly accurate vowel spectra to that already accomplished with the 1D version, although speech-like sounds created with the 2D mesh appear to exhibit greater realism.
Download Audio Processing Using Haskell The software for most today’s applications including signal processing applications is written in imperative languages. Imperative programs are fast because they are designed close to the architecture of the widespread computers, but they don’t match the structure of signal processing very well. In contrast to that, functional programming and especially lazy evaluation perfectly models many common operations on signals. Haskell is a statically typed, lazy functional programming language which allow for a very elegant and concise programming style. We want to sketch how to process signals, how to improve safety by the use of physical units, and how to compose music using this language.
Download The Sounding Gesture: An Overview Sound control by gesture is a peculiar topic in Human-Computer Interaction: many different approaches to it are available, focusing each time on diversified perspectives. Our point of view is an interdisciplinary one: taking into account technical considerations about control theory and sound processing, we try to explore the expressiveness world which is closer to psychology theories. Starting from a state of the art which outlines two main approaches to the problem of ”making sound with gestures”, we will delve into psychological theories about expressiveness, describing in particular possible applications dealing with intermodality and mixed reality environments related to the Gestalt Theory. HCI design can indeed benefit from this kind of approach because of the quantitative methods that can be applied to measure expressiveness. Interfaces can be used in order to convey expressiveness, which is a plus of information that can help interacting with the machine; this kind of information can be coded as spatio-temporal schemes, as it is stated in Gestalt theory.
Download A Piano Model Including Longitudinal String Vibrations In this paper a mixed-paradigm piano model is presented. The major development is the ability of modeling longitudinal string vibrations. Longitudinal string motion is the reason for the metallic sound of low piano notes, therefore its modeling greatly improves the perceptual quality of synthesized piano sound. In this novel approach the transversal displacement of the string is computed by a finite-difference string model and the longitudinal motion is calculated by a set of second-order resonators, which are nonlinearly excited by the transversal vibration. The soundboard is modeled by a multi-rate filter based on measurements of real pianos. The piano model is able to produce high-quality piano sounds in real-time with about 5–10 note polyphony on an average personal computer.
Download RoomWeaver: A Digital Waveguide Mesh Based Room Acoustics Research Tool RoomWeaver is a Digital Waveguide Mesh (DWM) based Integrated Development Environment (IDE) style research tool, similar in appearance and functionality to other current acoustics software. The premise of RoomWeaver is to ease the development and application of DWM models for virtual acoustic spaces. This paper demonstrates the basic functionality of RoomWeaver’s 3D modelling and Room Impulse Response (RIR) generation capabilities. A case study is presented to show how new DWM types can be quickly developed and easily tested using RoomWeaver’s built in plug-in architecture through the implementation of a hybrid-type mesh. This hybrid mesh is comprised of efficient, yet geometrically inflexible, finite difference DWM elements and the geometrically versatile, but slow, wave-based DWM elements. The two types of DWM are interfaced using a KW-pipe and this hybrid model exhibits a significant increase in execution speed and a smaller memory footprint than standard wave-based DWM models and allows nontrivial geometries to be successfully modelled.