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 Real-Time Implementation of a Friction Drum Inspired Instrument Using Finite Difference Schemes Physical modelling sound synthesis is a powerful method for constructing virtual instruments aiming to mimic the sound of realworld counterparts, while allowing for the possibility of engaging
with these instruments in ways which may be impossible in person.
Such a case is explored in this paper: particularly the simulation
of a friction drum inspired instrument. It is an instrument played
by causing the membrane of a drum head to vibrate via friction.
This involves rubbing the membrane via a stick or a cord attached
to its center, with the induced vibrations being transferred to the
air inside a sound box.
This paper describes the development of a real-time audio application which models such an instrument as a bowed membrane
connected to an acoustic tube. This is done by means of a numerical simulation using finite-difference time-domain (FDTD) methods in which the excitation, whose position is free to change in
real-time, is modelled by a highly non-linear elasto-plastic friction
model. Additionally, the virtual instrument allows for dynamically
modifying physical parameters of the model, thereby allowing the
user to generate new and interesting sounds that go beyond a realworld friction drum.
Download A Physical Model of the Trombone Using Dynamic Grids for Finite-Difference Schemes In this paper, a complete simulation of a trombone using finitedifference time-domain (FDTD) methods is proposed. In particular, we propose the use of a novel method to dynamically vary the
number of grid points associated to the FDTD method, to simulate
the fact that the physical dimension of the trombone’s resonator
dynamically varies over time. We describe the different elements
of the model and present the results of a real-time simulation.
Download Differentiable All-Pass Filters for Phase Response Estimation and Automatic Signal Alignment Virtual analog (VA) audio effects are increasingly based on neural networks and deep learning frameworks. Due to the underlying black-box methodology, a successful model will learn to approximate the data it is presented, including potential errors such as latency and audio dropouts as well as non-linear characteristics and frequency-dependent phase shifts produced by the hardware. The latter is of particular interest as the learned phase-response might cause unwanted audible artifacts when the effect is used for creative processing techniques such as dry-wet mixing or parallel compression. To overcome these artifacts we propose differentiable signal processing tools and deep optimization structures for automatically tuning all-pass filters to predict the phase response of different VA simulations, and align processed signals that are out of phase. The approaches are assessed using objective metrics while listening tests evaluate their ability to enhance the quality of parallel path processing techniques. Ultimately, an overparameterized, BiasNet-based, all-pass model is proposed for the optimization problem under consideration, resulting in models that can estimate all-pass filter coefficients to align a dry signal with its affected, wet, equivalent.
Download Doppler Simulation and the Leslie An efficient algorithm for simulating the Doppler effect using interpolating and de-interpolating delay lines is described. The Doppler simulator is used to simulate a rotating horn to achieve the Leslie effect. Measurements of a horn from a real Leslie are used to calibrate angle-dependent digital filters which simulate the changing, angle-dependent, frequency response of the rotating horn.