Download Sound synthesis by physical modelling using the functional transformation method: Efficient implementations with polyphase-filterbanks 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.
Download A Physically-Informed, Circuit-Bendable, Digital Model of the Roland TR-808 Bass Drum Circuit We present an analysis of the bass drum circuit from the classic Roland TR-808 Rhythm Composer, based on physical models of the device’s many sub-circuits. A digital model based on this analysis (implemented in Cycling 74’s Gen˜) retains the salient features of the original and allows accurate emulation of circuit-bent modifications—complicated behavior that is impossible to capture through black-box modeling or structured sampling. Additionally, this analysis will clear up common misconceptions about the circuit, support the design of further drum machine modifications, and form a foundation for circuit-based musicological inquiry into the history of analog drum machines.
Download Physical Model Parameter Optimisation for Calibrated Emulation of the Dallas Rangemaster Treble Booster Guitar Pedal In this work we explore optimising parameters of a physical circuit model relative to input/output measurements, using the Dallas Rangemaster Treble Booster as a case study. A hybrid metaheuristic/gradient descent algorithm is implemented, where the initial parameter sets for the optimisation are informed by nominal values from schematics and datasheets. Sensitivity analysis is used to screen parameters, which informs a study of the optimisation algorithm against model complexity by fixing parameters. The results of the optimisation show a significant increase in the accuracy of model behaviour, but also highlight several key issues regarding the recovery of parameters.
Download Object-Based Synthesis of Scraping and Rolling Sounds Based on Non-Linear Physical Constraints Sustained contact interactions like scraping and rolling produce a
wide variety of sounds. Previous studies have explored ways to
synthesize these sounds efficiently and intuitively but could not
fully mimic the rich structure of real instances of these sounds.
We present a novel source-filter model for realistic synthesis of
scraping and rolling sounds with physically and perceptually relevant controllable parameters constrained by principles of mechanics. Key features of our model include non-linearities to constrain
the contact force, naturalistic normal force variation for different
motions, and a method for morphing impulse responses within a
material to achieve location-dependence. Perceptual experiments
show that the presented model is able to synthesize realistic scraping and rolling sounds while conveying physical information similar to that in recorded sounds.
Download A String in a Room: Mixed-Dimensional Transfer Function Models for Sound Synthesis Physical accuracy of virtual acoustics receives increasing attention
due to renewed interest in virtual and augmented reality applications. So far, the modeling of vibrating objects as point sources
is a common simplification which neglects effects caused by their
spatial extent. In this contribution, we propose a technique for the
interconnection of a distributed source to a room model, based on
a modal representation of source and room. In particular, we derive a connection matrix that describes the coupling between the
modes of the source and the room modes in an analytical form.
Therefore, we consider the example of a string that is oscillating
in a room. Both, room and string rely on well established physical descriptions that are modeled in terms of transfer functions.
The derived connection of string and room defines the coupling
between the characteristic string and room modes. The proposed
structure is analyzed by numerical evaluations and sound examples
on the supplementary website.
Download Everyday sounds with the digital Intonarumori A digital simulation of the Intonarumori, musical instruments invented by the Italian Futurist composer and painter Luigi Russolo is proposed. By building physical models of different members of the Intonarumori family, a preservation of an important contribution to the musical heritage of the beginning of the 20th century is achieved.
Download Sound morphologies due to non-linear interactions : towards a perceptive control of environmental sound-synthesis processes This paper is concerned with perceptual control strategies for physical modeling synthesis of vibrating resonant objects colliding nonlinearly with rigid obstacles. For this purpose, we investigate sound morphologies from samples synthesized using physical modeling for non-linear interactions. As a starting point, we study the effect of linear and non-linear springs and collisions on a single-degreeof-freedom system and on a stiff strings. We then synthesize realistic sounds of a stiff string colliding with a rigid obstacle. Numerical simulations allowed the definition of specific signal patterns characterizing the non linear behavior of the interaction according to the attributes of the obstacle. Finally, a global description of the sound morphology associated with this type of interaction is proposed. This study constitutes a first step towards further perceptual investigations geared towards the development of intuitive synthesis controls.
Download Implementation of Arbitrary Linear Sound Synthesis Algorithms by Digital Wave Guide Structures The Digital Wave Guide (DWG) method is one of the most popular techniques for digital sound synthesis via physical modeling. Due to the inherent solution of the wave equation by the structure of the DWG method, it provides a highly efficient algorithm for typical physical modeling problems. In this paper it will be shown, that it is possible to use this efficient structure for any existing linear sound synthesis algorithm. By a consequent description of discrete implementations with State Space Structures (SSSs), suitable linear state space transformations can be used to achieve the typical DWG structure from any given system. The proposed approach is demonstrated with two case studies, where a modal solution achieved with the Functional Transformation Method (FTM) is transformed to a DWG implementation. In the first example the solution of the lossless wave equation is transformed to a DWG structure, yielding an arbitrary size fractional delay filter. In another example a more elaborated model with dispersion and damping terms is transformed, resulting in a DWG model with parameter morphing features.
Download Identification of Nonlinear Circuits as Port-Hamiltonian Systems This paper addresses identification of nonlinear circuits for
power-balanced virtual analog modeling and simulation. The proposed method combines a port-Hamiltonian system formulation
with kernel-based methods to retrieve model laws from measurements. This combination allows for the estimated model to retain
physical properties that are crucial for the accuracy of simulations,
while representing a variety of nonlinear behaviors. As an illustration, the method is used to identify a nonlinear passive peaking
EQ.
Download Discrete Implementation Of The First Order System Cascade As The Basis For A Melodic Segmentation Model The basis for a low-level melodic segmentation model and its discrete implementation is presented. The model is based on the discrete approximation of the one-dimensional convective transport mechanism. In this way, a physically plausible mechanism for achieving multi-scale representation is obtained. Some aspects of edge detection theory thought to be relevant for solving similar problems in auditory perception are briefly introduced. Two examples presenting the dynamic behaviour of the model are shown.