Download Compositional Sketches in PWGLSynth PWGLSynth has already a long history in controlling physicsbased instruments. The control system has been score-based, i.e. the user prepares a score in advance, and by interactive listening process the result can be be refined either by adjusting score information, performance rules and/or the visual instrument definition. This scheme allows detailed control on how the instrument model reacts to control information generated from the score. This paper presents a complementary approach to sound synthesis where the idea is to generate algorithmically typically relatively short musical textures. The user can improvise with various compositional ideas, adjust parameters, and listen to the results in real-time either individually or interleaved. This is achieved by utilizing a special code-box scheme that allows any textual Lisp expression to be interfaced to the visual part of the PWGL system.
Download Coefficient-modulated first-order allpass filter as distortion effect A novel approach to implement the distortion effect is introduced. The proposed approach is based on time-varying phase distortion of the input signal, and it is implemented using a coefficient modulated first-order allpass filter. This new technique provides control over the distorted band with a proper choice of the modulating signal. By choosing a modulating signal that applies the phase distortion only for low frequencies, the aliasing often generated by conventional distortion effects, which modify the signal amplitude, can be greatly reduced. Modulation signals that produce distortion effects applicable for electric guitar playing are also discussed. Sound examples on the use of the filter can be found at http://www.acoustics.hut.fi/~jpekonen/ Papers/dafx08/.
Download Musikverb: A Harmonically Adaptive Audio Reverberation We present MusikVerb, a novel digital reverberation capable of adapting its output to the harmonic context of a live music performance. The proposed reverberation is aware of the harmonic content of an audio input signal and ‘tunes’ the reverberation output to its harmonic content using a spectral filtering technique. The dynamic behavior of MusikVerb avoids the sonic clutter of traditional reverberation, and most importantly, fosters creative endeavor by providing new expressive and musically-aware uses of reverberation. Despite its applicability to any input audio signal, the proposed effect has been designed primarily as a guitar pedal effect and a standalone software application.
Download Granular analysis/synthesis of percussive drilling sounds This paper deals with the automatic and robust analysis, and the realistic and low-cost synthesis of percussive drilling like sounds. The two contributions are: a non-supervised removal of quasistationary background noise based on the Non-negative Matrix Factorization, and a granular method for analysis/synthesis of this drilling sounds. These two points are appropriate to the acoustical properties of percussive drilling sounds, and can be extended to other sounds with similar characteristics. The context of this work is the training of operators of working machines using simulators. Additionally, an implementation is explained.
Download Improved adjustable boundary condition for the 2-D finite-difference time-domain mesh The digital waveguide (DWG) mesh is a method for simulating wave propagation in multiple dimensions. Boundary conditions are needed for modeling changes in wave propagation media such as walls and furniture in a room or boundaries of a resonating membrane of a musical instrument. The boundary conditions have been solved for a one-dimensional DWG structure, but there is no known exact solution for the multi-dimensional mesh. In this work, a new boundary structure is introduced for modeling reflection coefficient values −1 ≤ r ≤ 1 in two dimensions. The new method gives remarkably more accurate results than the earlier approximations, especially at the low absolute values of r. At incident angles of Θ < 60o , the absolute error of reflection coefficient r is below 0.1 at frequencies 0.004 < f < 0.222 relative to the sampling frequency and at 60o ≤ Θ ≤ 80o the same result is reached at 0.005 < f < 0.114.
Download Digital Audio Device Creation by the use of a Domain Specific Language and a Hardware Abstraction Layer The present paper deals with a framework destined to manage different aspects of the creation of digital audio devices. By means of a domain-specific language modelling aspects like signal processing and user interaction are implemented. The problem of different hardware interfaces is resolved by the definition of a hardware abstraction layer. This layer provides different types of variables and functions. A compiler translates the model referring the functions and variables defined at the hardware abstraction layer. Furthermore, the compiler is able to split the model into different parts that can be run on different hardware components. The communication needed to manage the distributed model is defined and formalized by the framework. A simple example is presented to help explain the framework’s parts, as are the compiler and the execution unit.
Download A Preliminary Model for the Synthesis of Source Spaciousness We present here a basic model for the synthesis of source spaciousness over loudspeaker arrays. This model is based on two experiments carried out to quantify the contribution of early reflections and reverberation to the perception of source spaciousness.
Download Optimal Integer Order Approximation of Fractional Order Filters Fractional order filters have been studied since a long time,
along with their applications to many areas of physics and engineering. In particular, several solutions have been proposed in
order to approximate their frequency response with that of an ordinary filter. In this paper, we tackle this problem with a new approach: we solve analytically a simplified version of the problem
and we find the optimal placement of poles and zeros, giving a
mathematical proof and an error estimate. This solution shows improved performance compared to the current state of the art and is
suitable for real-time parametric control.
Download Morphing of granular sounds Granular sounds are commonly used in video games but the conventional approach of using recorded samples does not allow sound designers to modify these sounds. In this paper we present a technique to synthesize granular sound whose tone color lies at an arbitrary point between two given granular sound samples. We first extract grains and noise profiles from the recordings, morph between them and finally synthesize sound using the morphed data. During sound synthesis a number of parameters, such as the number of grains per second or the loudness distribution of the grains, can be altered to vary the sound. The proposed method does not only allow to create new sounds in real-time, it also drastically reduces the memory footprint of granular sounds by reducing a long recording to a few hundred grains of a few milliseconds length each.
Download A Two Level Montage Approach to Sound Texture Synthesis with Treatment of Unique Events In this paper a novel algorithm for sound texture synthesis is presented. The goal of this algorithm is to produce new examples of a given sampled texture, the synthesized textures being of any desired duration. The algorithm is based on a montage approach to synthesis in that the synthesized texture is made up of pieces of the original sample concatenated together in a new sequence. This montage approach preserves both the high level evolution and low level detail of the original texture. Included in the algorithm is a measure of uniqueness, which can be used for the identification of regions in the original texture containing events that are atypical of the texture, and hence avoid their unnatural repetition at the synthesis stage.