Download Modelling and Separation of Singing Voice Breathiness in Polyphonic Mixtures Most current source separation methods only target the voiced component of the singing voice. Besides the unvoiced consonant phonemes, the remaining breathiness is very noticeable to humans and it retains much of the phonetic and timbral information from the singer. We propose a low-latency method for estimating the spectrum of the breathiness component, which is taken into account when isolating the singing voice source from the mixture. The breathiness component is derived from the detected harmonic envelope in pitched vocal sounds. The separation of the voiced components is used in conjunction with an existing iterative approach based on spectrum factorization. Finally, we conduct an objective evaluation that demonstrates the separation improvement, supported also by a number of audio examples.
Download Audio-Tactile Glove This paper introduces the Audio-Tactile Glove, an experimental tool for the analysis of vibrotactile feedback in instrument design. Vibrotactile feedback provides essential information in the operation of acoustic instruments. The Audio-Tactile Glove is designed as a research tool for the investigation of the various techniques used to apply this theory to digital interfaces. The user receives vibrations via actuators distributed throughout the glove, located so as not to interrupt the physical contact required between user and interface. Using this actuator array, researchers will be able to independently apply vibrotactile information to six stimulation points across each hand exploiting the broad frequency range of the device, with specific sensitivity within the haptic frequency range of the hand. It is proposed that researchers considering the inclusion of vibrotactile feedback in existing devices can utilize this device without altering their initial designs.
Download Stereo Vocal Extraction Using Adress and Nearest Neighbours Median Filtering An efficient and effective stereo vocal extraction algorithm is presented, which combines two existing approaches. A Nearest Neighbours Median Filtering algorithm is used to separate the vocals and the instrumental backing track from the stereo mixture. The separated vocal track is then passed through a mask generated by the Adress algorithm and high-pass filtered to extract the vocals. The separated instrumental backing track is then improved by adding to it the residual backing track energy extracted by Adress. Also investigated is a variant on this algorithm which uses a difference spectrogram to calculate the nearest neighbours. The effectiveness of these algorithms is then demonstrated on a test dataset, and results show that the proposed algorithms give performance comparable to the state of the art, but at a low computational cost.
Download Timbre-Constrained Recursive Time-Varying Analysis for Musical Note Separation Note separation in music signal processing becomes difficult when there are overlapping partials from co-existing notes produced by either the same or different musical instruments. In order to deal with this problem, it is necessary to involve certain invariant features of musical instrument sounds into the separation processing. For example, the timbre of a note of a musical instrument may be used as one possible invariant feature. In this paper, a timbre estimate is used to represent this feature such that it becomes a constraint when note separation is performed on a mixture signal. To demonstrate the proposed method, a timedependent recursive regularization analysis is employed. Spectral envelopes of different notes are estimated and a modified parameter update strategy is applied to the recursive regularization process. The experiment results show that the flaws due to the overlapping partial problem can be effectively reduced through the proposed approach.
Download Comparison of Various Predictors for Audio Extrapolation In this study, receiver-based audio error concealment in the context of low-latency Audio over IP transmission is analyzed. Therefore, the well-known technique of audio extrapolation is investigated concerning its usability in real-time scenarios, its applied prediction techniques and various transmission parameters. A large-scale automated evaluation with PEAQ and a MUSHRA listening test reveal the performance of the various extrapolation setups. The results show the suitability of extrapolation to perform audio error concealment in real-time and the qualitative superiority of block based methods over sample based methods.
Download Kronos VST – The Programmable Effect Plugin This paper introduces Kronos VST, an audio effect plugin conforming to the VST 3 standard that can be programmed on the fly by the user, allowing entire signal processors to be defined in real time. A brief survey of existing programmable plugins or development aids for audio effect plugins is given. Kronos VST includes a functional just in time compiler that produces high performance native machine code from high level source code. The features of the Kronos programming language are briefly covered, followed by the special considerations of integrating user programs into the VST infrastructure. Finally, introductory example programs are provided.
Download A Digital Model of the Buchla Lowpass-Gate In recent years there has been an increasing amount of interest in the style of synthesis implemented by Don Buchla in his instrument designs from the early 1960s until the present. A key part of the Buchla synthesizer and its characteristic quality is the ’lowpass gate’ filter and the acoustic-like plucked sounds that it provides. In this work we examine the circuit of the low-pass gate, both its audio and control portions. We propose a number of digital models of these circuits, as well as a model of the photoresistive optoisolator or ’vactrol’ used within them. In the case of the audio path of the device, we pay particular attention to maintaining desirable behavior under time-variation of its parameters. The resulting digital model retains much of the interesting character of the analog system, and is computationally cheap enough to use within a standard computer-music setup.
Download Doppler Effects without Equations We present a fast and robust method for approximating sound propagation in situations where audio and video frame rates may differ significantly and positions of sound sources and listeners are only known at discrete times, so that numerically stable velocities are not available. Typical applications include 3D scenes in virtual environments where positions of sources and listeners are determined in real time by user interaction. Our method employs a computationally inexpensive heuristic that converges to the exact solution for constant speeds and achieves convincing Doppler shifts in general.
Download Csoundo For Android The Csoundo library combines the sound compiler Csound with Processing, a java-based programming language for visual applets. The combination of the two provides a framework for the rapid development of interactive audio-visual applications. Csound and Processing have recently been ported to the Android platform so these languages may now be used to develop applications directly for Android devices. However, at present, Csound for Android has only been implemented with basic Android Graphical User Interface(GUI) elements while Processing for Android lacks support for external libraries, including its established audio libraries. Csoundo for Android bridges the gap between the two languages and allows developers to rapidly build interactive audio applications without having to be concerned about the inner-workings of Android development.
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.