Download Expressive Controllers For Bowed String Physical Models In this paper we propose different approaches to control a real-time physical model of a bowed string instrument. Starting from a commercially available device, we show how to improve the gestural control of the model.
Download CYMATIC: A tactile controlled physical modelling instrument 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.
Download BLOCKCOMPILER – A research tool for physical modelling and DSP 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.
Download Optimization techniques for a physical model of human vocalisation We present a non-supervised approach to optimize and evaluate the synthesis of non-speech audio effects from a speech production model. We use the Pink Trombone synthesizer as a case study of a simplified production model of the vocal tract to target nonspeech human audio signals –yawnings. We selected and optimized the control parameters of the synthesizer to minimize the difference between real and generated audio. We validated the most common optimization techniques reported in the literature and a specifically designed neural network. We evaluated several popular quality metrics as error functions. These include both objective quality metrics and subjective-equivalent metrics. We compared the results in terms of total error and computational demand. Results show that genetic and swarm optimizers outperform least squares algorithms at the cost of executing slower and that specific combinations of optimizers and audio representations offer significantly different results. The proposed methodology could be used in benchmarking other physical models and audio types.
Download A Physically-motivated Triode Model for Circuit Simulations A new model for triodes of type 12AX7 is presented, featuring simple and continuously differentiable equations. The description is physically-motivated and enables a good replication of the grid current. Free parameters in the equations are fitted to reference data originated from measurements of practical triodes. It is shown, that the equations are able to characterize the properties of real tubes in good accordance. Results of the model itself and when embedded in an amplifier simulation are presented and align well.
Download Real-Time Physical Modelling For Analog Tape Machines For decades, analog magnetic tape recording was the most popular method for recording music, but has been replaced over the past 30 years first by DAT tape, then by DAWs and audio interfaces. Despite being replaced by higher quality technology, many have sought to recreate a "tape" sound through digital effects, despite the distortion, tape "hiss", and other oddities analog tape produced. The following paper describes the general process of creating a physical model of an analog tape machine starting from basic physical principles, then discusses in-depth a real-time implementation of a physical model of a Sony TC-260 tape machine."Whatever you now find weird, ugly, uncomfortable, and nasty about a new medium will surely become its signature. CD distortion, the jitteriness of digital video, the crap sound of 8-bit - all of these will be cherished and emulated as soon as they can be avoided." -Brian Eno.
Download The voice of the dragon: A physical model of a rotating corrugated tube 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.
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 Physically inspired signal model for harmonium sound synthesis The hand harmonium is arguably the most popular instrument for vocal accompaniment in Hindustani music today. However, it lacks microtonality and the ability to produce controlled pitch glides, which are both important in Hindustani music. A harmonium sound synthesis model with a source-filter structure was previously presented by the authors in which the harmonium reed sound is synthesized using a physical model and the effect of the wooden enclosure is applied by a filter estimated from a recorded note. In this paper, we propose a simplified and perceptually informed signal model capable of real time synthesis with timbre control. In the signal model, the source is constructed as a band-limited waveform matching the spectral characteristics of the source signal in the physical model. Simplifications are suggested to parametrize the filter on the basis of prominent peaks in the filter frequency response. The signal model is implemented as a Pure Data [1] patch for live performance using a standard MIDI keyboard.