1,721,207 research outputs found
SAMPLE: a Python Package for the Spectral Analysis of Modal Sounds
Full text linkWe present SAMPLE, a Python package of tools for spectral analysis and modal parameters estimate. The core of the package is an implementation of the “Spectral Analysis for Modal Parameters Linear Estimate” (SAMPLE) algorithm. This includes a custom implementation of a Sinusoidal Analysis algorithm based on Spectral Modelling Synthesis. Our custom implementation is specifically designed for modal tracking. We also included utilities for automatically tuning the algorithm parameters, using a Bayesian optimization method based on Gaussian Processes. For this purpose, we implemented efficient routines for computing perceptual audio representations for loss functions, such as the multiscale-spectrogram, the mel-spectrogram and the cochleagram. The package also comes with a Graphical User Interface, which allows to load and trim audio inputs, set the algorithm parameters, run the algorithm, listen to a resynthesis of the input, and export the results. The GUI is distributed both as an extra for the Python package and as a standalone executable
Modeling Collision Sounds: Non-Linear Contact Force
No full textA model for physically based synthesis of collision sounds is proposed. Attention is focused on the non-linear contact force, for which both analytical and experimental results are presented. Numerical implementation of the model is discussed, with regard to accuracy and efficiency issues. As an application, a physically based audio effect is presented
Modelling the mechanical response of the Reed-mouthpiece-lip system of a clarinet : Part I. A one-dimensional distributed model
No full textThe motion of a clarinet reed that is clamped to a mouthpiece and supported by a lip is simulated in the time domain using finite difference methods. The reed is modelled as a bar with non-uniform cross section, and is described using a one-dimensional, fourth-order partial differential equation. The interactions with the mouthpiece lay and the player's lip are taken into account by incorporating conditional contact forces in the bar equation. The model is completed by clamped-free boundary conditions for the reed. An implicit finite difference method is used for discretising the system, and values for the physical parameters are chosen both from laboratory measurements and by accurate tuning of the numerical simulations. The accuracy of the numerical system is assessed through analysis of frequency warping effects and of resonance estimation. Finally, the mechanical properties of the system are studied by analysing its response to external driving forces. In particular, the effects of reed curling are investigated
Virtual analogue instruments: an approach to active preservation of the studio di fonologia musicale
No full textElectroacoustic music is a young form of art. Nevertheless, it is still necessary to take care of its preservation, due to the limited life of the recording supports, of the reading systems of the data, and of the instruments. Moreover, preservation and restoration of electroacoustic music works raise peculiar technical and philological issues. With particular regard to electrophone instruments, many technological generations have passed since the appearance of the first instruments, and many electronic components used in their construction do not exist anymore or are only available with difficulty.
Electrophones are considered to be the only musical instruments which produce sound primarily by electrical means. Electrophones are one of the five main categories in the Hornbostel-Sachs scheme of musical instrument classification.156 Although this category is not included in the original scheme published in 1914, it was added by Sachs in 1940,157 to describe instruments involving electricity.
Preservation of supports, reading devices, and instruments of electroacoustic music requires specific knowledge, adequate funding within institutional frameworks, and interdisciplinary collaboration among several experts in the field, because damage produced by unsuitable preservation or inadequate restoration is irreversible. Production by composers is considerable: already in 1967 Hugh Davies had catalogued world-wide around 5000 electroacoustic music works,158 and this number is today much larger.
Alarm bells are already ringing, and recent years have seen increasing attention to these issues, and a growing awareness of how precarious the passive preservation of this cultural heritage of the recent past can be. The EU is particularly sensitive to these issues: an example of this awareness is the EU-funded DREAM project,159 whose results are discussed in this essay. This project defines an approach to an active preservation of the electrophone instruments of the SdF, and is one of the first attempts to address this issue from a multidisciplinary perspective involving engineering, interaction design, and musicological competences. The final goal is to develop an installation consisting of a software-hardware system that re-creates the electronic lutherie of the SdF, allowing users (both musicians and amateurs) to interact with such lutherie. Achieving this goal implies: i. analysing the devices through project schemes and direct inspection; ii. validating the analysis through simulations with ad hoc tools; iii. developing physical models of the analogue devices, which allow efficient and accurate numerical simulations of their functioning; iv. designing appropriate interfaces to interact with the virtual devices.
In order to illustrate this process, some specific electrophone instruments of the SdF, the early sinusoidal oscillators and the so-called amplitude selector, will be considered in this essay as relevant case studies, both from a technical and from a historical and musicological viewpoints
Simulation of vocal fold oscillation with a pseudo-one-mass physical model
Full text linkThis paper presents a novel ``pseudo-one-mass model'' of the vocal folds, which is derived from a previously proposed two-mass model. Two-mass models account for effects of vertical phase differences in fold motion by means of a pair of coupled oscillators that describe the lower and upper fold portions. Instead, the proposed model employs a single mass-spring oscillator to describe only the oscillation of the lower fold portion, while phase difference effects are simulated through an approximate phenomenological description of the upper glottal area. This approximate description is derived in the hypothesis that modal entrainment occurs between the two masses in the large-amplitude oscillation regime, and is then exploited to derive the equations of the pseudo-one-mass model. Numerical simulations of the reference two-mass model are analyzed to show that the proposed approximation remains valid when values of the physical parameters are varied in a large region of the control space. The effects on the shape of the glottal flow pulse are also analyzed. Comparison of simulations with the reference two-mass model and the pseudo-one-mass model show that the dynamic behavior of the former is accurately approximated by the latter. The similarity of flow signals synthesized with the two models is assessed in terms of four acoustic parameters: fundamental frequency, maximum amplitude, open quotient, and speed quotient. The results confirm that the pseudo-one-mass model fit with good accuracy the behavior of the reference two-mass model, while requiring significantly lower computational resources and roughly half of the mechanical parameters
Modeling Interactions between Rubbed Dry Surfaces using an Elasto-Plastic Friction Model
No full text
- …
