Download Physical Model of the String-Fret Interaction In this paper, a model for the interaction of the strings with the frets in a guitar or other fretted string instruments is introduced. In the two-polarization representation of the string oscillations it is observed that the string interacts with the fret in different ways. While the vertical oscillation is governed by perfect or imperfect clamping of the string on the fret, the horizontal oscillation is subject to friction of the string over the surface of the fret. The proposed model allows, in particular, for the accurate evaluation of the elongation of the string in the two modes, which gives rise to audible dynamic detuning. The realization of this model into a structurally passive system for use in digital waveguide synthesis is detailed. By changing the friction parameters, the model can be employed in fretless instruments too, where the string directly interacts with the neck surface.
Download Gestural Auditory and Visual Interactive Platform This paper introduces GAVIP, an interactive and immersive platform allowing for audio-visual virtual objects to be controlled in real-time by physical gestures and with a high degree of intermodal coherency. The focus is particularly put on two scenarios exploring the interaction between a user and the audio, visual, and spatial synthesis of a virtual world. This platform can be seen as an extended virtual musical instrument that allows an interaction with three modalities: the audio, visual and spatial modality. Intermodal coherency is thus of particular importance in this context. Possibilities and limitations offered by the two developed scenarios are discussed and future work presented.
Download Nonlinear Allpass Ladder Filters in FAUST Passive nonlinear filters provide a rich source of evolving spectra for sound synthesis. This paper describes a nonlinear allpass filter of arbitrary order based on the normalized ladder filter. It is expressed in FAUST recursively in only two statements. Toward the synthesis of cymbals and gongs, it was used to make nonlinear waveguide meshes and feedback-delay-network reverberators.
Download Harpsichord Sound Synthesis using a Physical Plectrum Model Interfaced with the Digital Waveguide In this paper, we present a revised model of the plectrum-string interaction and its interface with the digital waveguide for simulation of the harpsichord sound. We will first revisit the plectrum body model that we have proposed previously in [1] and then extend the model to incorporate the geometry of the plectrum tip. This permits us to model the dynamics of the string slipping off the plectrum more comprehensively, which provides more physically accurate excitation signals. Simulation results are presented and discussed.
Download Mapping blowing pressure and sound features in recorder playing This paper presents a data-driven approach to the construction of mapping models relating sound features and blowing pressure in recorder playing. Blowing pressure and sound feature data are synchronously obtained from real performance: blowing pressure is measured by means of a piezoelectric transducer inserted into the mouth piece of a modified recorder, while produced sound is acquired using a close-field microphone. Acquired sound is analyzed frame-by-frame, and features are extracted so that original sound can be reconstructed with enough fidelity. A multi-modal database of aligned blowing pressure and sound feature signals is constructed from real performance recordings designed to cover basic performance contexts. Out of the gathered data, two types of mapping models are constructed using artificial neural networks: (i) a model able to generate sound feature signals from blowing pressure signals, and therefore used to produce synthetic sound from recorded blowing pressure profiles via additive synthesis; and (ii) a model able to estimate the blowing pressure from extracted sound features.
Download Modal analysis of impact sounds with ESPRIT in Gabor transforms Identifying the acoustical modes of a resonant object can be achieved by expanding a recorded impact sound in a sum of damped sinusoids. High-resolution methods, e.g. the ESPRIT algorithm, can be used, but the time-length of the signal often requires a sub-band decomposition. This ensures, thanks to sub-sampling, that the signal is analysed over a significant duration so that the damping coefficient of each mode is estimated properly, and that no frequency band is neglected. In this article, we show that the ESPRIT algorithm can be efficiently applied in a Gabor transform (similar to a sub-sampled short-time Fourier transform). The combined use of a time-frequency transform and a high-resolution analysis allows selective and sharp analysis over selected areas of the time-frequency plane. Finally, we show that this method produces high-quality resynthesized impact sounds which are perceptually very close to the original sounds.
Download A Parametric Model of Piano Tuning A parametric model of aural tuning of acoustic pianos is presented in this paper. From a few parameters, a whole tessitura model is obtained, that can be applied to any kind of pianos. Because the tuning of piano is strongly linked to the inharmonicity of its strings, a 2-parameter model for the inharmonicity coefficient along the keyboard is introduced. Constrained by piano string design considerations, its estimation requires only a few notes in the bass range. Then, from tuning rules, we propose a 4-parameter model for the fundamental frequency evolution on the whole tessitura, taking into account the model of the inhamonicity coefficient. The global model is applied to 5 different pianos (4 grand pianos and
Download Audio De-Thumping using Huang s Empirical Mode Decomposition In the context of audio restoration, sound transfer of broken disks usually produces audio signals corrupted with long pulses of low-frequency content, also called thumps. This paper presents a method for audio de-thumping based on Huang’s Empirical Mode Decomposition (EMD), provided the pulse locations are known beforehand. Thus, the EMD is used as a means to obtain pulse estimates to be subtracted from the degraded signals. Despite its simplicity, the method is demonstrated to tackle well the challenging problem of superimposed pulses. Performance assessment against selected competing solutions reveals that the proposed solution tends to produce superior de-thumping results.
Download Vivos Voco: A survey of recent research on voice transformations at IRCAM IRCAM has a long experience in analysis, synthesis and transformation of voice. Natural voice transformations are of great interest for many applications and can be combine with text-to-speech system, leading to a powerful creation tool. We present research conducted at IRCAM on voice transformations for the last few years. Transformations can be achieved in a global way by modifying pitch, spectral envelope, durations etc. While it sacrifices the possibility to attain a specific target voice, the approach allows the production of new voices of a high degree of naturalness with different gender and age, modified vocal quality, or another speech style. These transformations can be applied in realtime using ircamTools TR A X.Transformation can also be done in a more specific way in order to transform a voice towards the voice of a target speaker. Finally, we present some recent research on the transformation of expressivity.
Download Time-Variant Delay Effects based on Recurrence Plots Recurrence plots (RPs) are two-dimensional binary matrices used to represent patterns of recurrence in time series data, and are typically used to analyze the behavior of non-linear dynamical systems. In this paper, we propose a method for the generation of time-variant delay effects in which the recurrences in an RP are used to restructure an audio buffer. We describe offline and realtime systems based on this method, and a realtime implementation for the Max/MSP environment in which the user creates an RP graphically. In addition, we discuss the use of gestural data to generate an RP, suggesting a potential extension to the system. The graphical and gestural interfaces can provide an intuitive and convenient way to control a time varying delay.