Download A Streaming Audio Mosaicing Vocoder Implementation
This paper introduces a new extension to the concept of Audio Mosaicing, a process by which a set of unrelated sounds are blended together to form a new audio stream of shared sonic characteristics. The proposed approach is based on the algorithm that underlies the well-known channel vocoder, that is, it splits the input signals into frequency bands, which are then processed individually, and then recombined to form the output. In a similar manner, our mosaicing scheme first uses filterbanks to decompose the set of input audio segments. Then, it introduces the use of Dynamic Time Warping to perform the matching process across the filterbank outputs. Following this, the re-synthesis stage includes a bank of Phase Vocoders, one for each frequency band to facilitate targeted spectral and temporal musical effects prior to recombination. Using multiple filterbanks means that this algorithm lends itself well to parallelisation and it is also shown how computational efficiencies are achieved that permit a real-time implementation.
Download Navigating in a Space of Synthesized Interaction-Sounds: Rubbing, Scratching and Rolling Sounds
In this paper, we investigate a control strategy of synthesized interaction-sounds. The framework of our research is based on the action/object paradigm that considers that sounds result from an action on an object. This paradigm presumes that there exists some sound invariants, i.e. perceptually relevant signal morphologies that carry information about the action or the object. Some of these auditory cues are considered for rubbing, scratching and rolling interactions. A generic sound synthesis model, allowing the production of these three types of interaction together with a control strategy of this model are detailed. The proposed control strategy allows the users to navigate continuously in an ”action space”, and to morph between interactions, e.g. from rubbing to rolling.
Download A Modeller-Simulator for Instrumental Playing of Virtual Musical Instruments
This paper presents a musician-oriented modelling and simulation environment for designing physically modelled virtual instruments and interacting with them via a high performance haptic device. In particular, our system allows restoring the physical coupling between the user and the manipulated virtual instrument, a key factor for expressive playing of traditional acoustical instruments that is absent in the vast majority of computer-based musical systems. We first analyse the various uses of haptic devices in Computer Music, and introduce the various technologies involved in our system. We then present the modeller and simulation environments, and examples of musical virtual instruments created with this new environment.
Download Rumbator: a Flamenco Rumba Cover Version Generator Based on Audio Processing at Note Level
In this article, a scheme to automatically generate polyphonic flamenco rumba versions from monophonic melodies is presented. Firstly, we provide an analysis about the parameters that defines the flamenco rumba, and then, we propose a method for transforming a generic monophonic audio signal into such a style. Our method firstly transcribes the monophonic audio signal into a symbolic representation, and then a set of note-level audio transformations based on music theory is applied to the monophonic audio signal in order to transform it to the polyphonic flamenco rumba style. Some audio examples of this transformation software are also provided.
Download Controlling a Non Linear Friction Model for Evocative Sound Synthesis Applications
In this paper, a flexible strategy to control a synthesis model of sounds produced by non linear friction phenomena is proposed for guidance or musical purposes. It enables to synthesize different types of sounds, such a creaky door, a singing glass or a squeaking wet plate. This approach is based on the action/object paradigm that enables to propose a synthesis strategy using classical linear filtering techniques (source/resonance approach) which provide an efficient implementation. Within this paradigm, a sound can be considered as the result of an action (e.g. impacting, rubbing, ...) on an object (plate, bowl, ...). However, in the case of non linear friction phenomena, simulating the physical coupling between the action and the object with a completely decoupled source/resonance model is a real and relevant challenge. To meet this challenge, we propose to use a synthesis model of the source that is tuned on recorded sounds according to physical and spectral observations. This model enables to synthesize many types of non linear behaviors. A control strategy of the model is then proposed by defining a flexible physically informed mapping between a descriptor, and the non linear synthesis behavior. Finally, potential applications to the remediation of motor diseases are presented. In all sections, video and audio materials are available at the following URL: thoretDAFx2013/
Download TELTPC Based Re-Synthesis Method for Isolated Notes of Polyphonic Instrumental Music Recordings
In this paper, we presented a flexible analysis/re-synthesis method for smoothly changing the properties of isolated notes in polyphonic instrumental music recordings. True Envelope Linear Predictive Coding (TELPC) method has been employed as the analysis/synthesis model in order to preserve the original timbre quality as much as possible due to its accurate spectral envelope estimation. We modified the conventional LPC analysis/synthesis processing by using pitch synchronous analysis frames to avoid the severe magnitude modulation problem. Smaller frames can thus be used to capture more local characteristics of the original signals to further improve the sound quality. In this framework, one can manipulate a sequence of isolated notes from two commercially available polyphonic instrumental music recordings and interesting re-synthesized results are achieved.
Download Time-Frequency Analysis of Musical Signals using the Phase Coherence
In this paper we propose a technique based on the phase evolution of the Short Time Fourier Transform (STFT) for increasing the spectral resolution in the time-frequency analysis of a musical signal. It is well known that the phase evolution of the STFT coefficients brings important information on the spectral components of the analysed signal. This property has already been exploited in different ways to improve the accuracy in the estimation of the frequency of a single component. In this paper we propose a different approach, where all the coefficients of the STFT are used jointly to build a measure of how likely all the frequency components are, in terms of their phase coherence evaluated in consecutive analysis window. In more detail, we construct a phase coherence function which is then integrated with the usual amplitude spectrum to obtain a refined description of the spectral components of an audio signal.
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.