Simulations of modal active control applied to the self-sustained oscillations of the clarinet

Modal active control enables modifications of the damping and the frequencies of the different resonances of a system. A self-sustained oscillating wind instrument is modelled as a disturbance coupled to a resonator through a non-linear coupling. The aim of this study is to present simulations of modal active control applied to a modeled simplified self-sustained oscillating wind instrument (e.g. a cylindrical tube coupled to a reed, which is considered to approximate a simplified clarinet), incorporating collocated speaker, microphone and a reed. The next goal will be to apply this control experimentally and to test it with musicians

How far can the resonance frequencies give informations about the playing frequencies? The trumpet example

International audienceMeasurements and calculations of the input impedance of wind musical instruments are now well mastered. The purpose of this work is to study experimentally how far the resonance frequencies of brass instruments, taken from their input impedance, are able to give informations about the playing frequencies. Three different trumpets, obtained by changing only the leadpipe of the same instrument, were considered for the experiment. After a measurement of the input impedance of these trumpets, four musicians were asked to play the five first playable notes (regimes 2 to 6), for four different fingerings. This exercise was done for three nuances and was repeated three times. Finally, these 3×4×5×4×3×3=2160 notes allow us to make a quantitative assessment of the relations between the resonance frequencies and the playing frequencies. Results show first, a limited influence of the musician on the overall intonation of the instrument. Second, the pitch of the notes does not vary much with the nuances. Finally, the results confirm the fact that variations of the resonance frequencies lead to variations of the playing frequencies of the same order

An active mute for the trombone

A mute is a device that is placed in the bell of a brass instrument to alter its sound. However, when a straight mute is used with a brass instrument, the frequencies of its first impedance peaks are slightly modified, and a mistuned, extra impedance peak appears. This peak affects the instrument’s playability, making some lower notes difficult or impossible to produce when playing at low dynamic levels. To understand and suppress this effect, an active mute with embedded microphone and speaker has been developed. A control loop with gain and phase shifting is used to control the damping and frequency of the extra impedance peak. The stability of the controlled system is studied and then the effect of the control on the input impedance and radiated sound of the trombone is investigated. It is shown that the playability problem results from a decrease in the input impedance magnitude at the playing frequency, caused by a trough located on the low frequency side of the extra impedance peak. When the extra impedance peak is suppressed, the playability of the note is restored. Meanwhile, when the extra impedance peak is moved in frequency, the playability problem position is shifted as well

Effet des différentes sourdines sur l'acoustique des instruments à vent de la famille des " cuivres ".

National audienceCe texte sur la compréhension des phénomènes acoustiques engendrés par les sourdines est un exemple d'application des notions générales définies dans le dossier Acoustique des instruments à vent du numéro 5 de la revue " musique & technique ". Parmi celles-ci mentionnons les notions de régime de fonctionnement, d'excitation forcée du résonateur pour la mesure des résonances, d'harmonicité (ou inharmonicité) des fréquences propres, de sons " pathologiques ", etc. Certains points relatifs aux sourdines ne serons pas abordés ici, comme la notation, les problèmes pratiques de mise en place, l'encombrement, la fiabilité, le confort ..., points liés principalement à l'utilisation musicale des sourdines par les musiciens, interprètes ou compositeurs

Reconstitution Virtuelle des Trompes (cornua) de Pompéi par la Synthèse dite par Modélisation Physique

International audienceCe projet multidisciplinaire (sciences humaines, acoustique, science des matériaux, facture instrumentale, synthèse sonore et musique) s’inscrit dans le programme “ Paysages sonores et espaces urbains de la Méditerranée ancienne ” porté par les trois Écoles de l’étranger (EFR Rome ; EFA Athènes et IFAO Le Caire). La présentation insistera principalement sur l’étude acoustique et la réalisation de copies virtuelles de ces trompes antiques découvertes en 1852 et 1884. Dans les réserves du Musée Archéologique de Naples, cinq reconstitutions incomplètes de cornu ont été analysées. Issues d’une dérestauration de 1979, ces reconstitutions sont composées de différents fragments montés sur un tube en plexiglass fixé sur une planche, rendant l’étude difficile en particulier pour le relevé de la perce. Deux embouchures aux dimensions légèrement différentes ont complété l’ensemble analysé. L’objectif de cette facette de l’étude était de répondre à de nombreuses interrogations dont certaines sont listées à la suite : - peut-on considérer que la reconstitution actuelle est correcte étant donné l’état de conservation des cornua ? - existe-t-il des différences entre les cinq instruments ? - quelles notes pouvaient-ils émettre ? Avec quelle justesse, quel timbre, quelle facilité, quellepuissance, etc. ? Pour quel diapason ? Pour y répondre, nous nous sommes appuyés en outre sur nos connaissances actuelles sur les instruments à vent de type cuivres et sur les outils de CAO comme le logiciel Resonans, permettant de calculer les résonances de l’instrument pour une perce donnée. Pour la synthèse sonore, nous avons utilisé le logiciel Modalys qui exploite la décomposition modale des reconstitutions calculées. Les travaux des collaborateurs de ce projet concernant les matériaux, la fabrication, l’histoire, les écrits de l’époque mais aussi les copies réalisées à la fin du XIXesiècle par le facteur V.-Ch. Mahillon ont été d’une aide précieuse pour cette étude

Active control applied to simplified wind musical instrument

Active control is widely used in industry. However, there have been relatively few applications to musical instruments, particularly wind instruments. The aim of this study is to attempt to control the sound quality and playability of wind instruments, using active control. Active control makes it possible to modify the input impedance (amplitude and frequency) of an instrument and to modify the instrument's quality. Simulations and first experiments on a cylindrical tube, which is considered to be a simple wind instrument, with embedded microphone and speaker are presented. Finally, the effects on the sound and the input impedance of the instrument are studied

La facture des trompes : étude acoustique et métallurgique, essai de modélisation

OCLC: 1143468637International audienceL'apport de Pompéi à l'archéologie musicale de l'Antiquité est rarement mis en avant ; il peut se mesurer à l'aune des vestiges d'instruments de musique découverts sur le site. Cinq grandes trompettes courbes, que les Romains nommaient cornua, sont au nombre des artefacts mis au jour au XIXe siècle dans les ruines de la cité. Bien connues des soldats de l'armée romaine, elles étaient utilisées aussi dans la vie municipale lors des rites civiques et, plus encore, pour scander les temps forts des combats de gladiateurs dans l'amphithéâtre.0Cet ouvrage, fruit d'une collaboration interdisciplinaire entre plusieurs spécialistes, reprend l'intégralité du dossier dans toute sa diversité : histoire des découvertes et des restaurations, muséographie, mise en série avec les autres vestiges connus, iconographie, lexicographie, usages sociaux. Enfin, l'analyse métallurgique et l'étude acoustique permettent de mesurer l'apport des nouvelles technologies dans la restitution sonore

The representation of auditory source characteristics: Simple geometric form

Two experiments examined listeners’ ability to discriminate the geometric shape of simple resonating bodies on the basis of their corresponding auditory attributes. In cross-modal matching tasks, subjects listened to recordings of pairs of metal bars (Experiment 1) or wooden bars (Experiment 2) struck in sequence and then selected a visual depiction of the bar cross sections that correctly represented their relative widths and heights from two opposing pairs presented on a computer screen. Multidimensional scaling solutions derived from matching scores for metal and wooden bars indicated that subjects’ performance varied directly with increasing differences in the width/height (WIH) ratios of both sets of bars. Subsequent acoustic analyses revealed that the frequency components from torsional vibrational modes and the ratios of frequencies of transverse bending modes in the bars correlated strongly with both the bars’ WIH ratios and bar coordinates in the multidimensional configurations. The results suggest that listeners can encode the auditory properties of sound sources by extracting certain invariant physical characteristics of their gross geometric properties from their acoustic behavior

Modalys, a physical modeling synthesizer: More than twenty years of researches, developments, and musical uses

cote interne IRCAM: Causse11dNone / NoneInternational audienceIn the early 1990s, the software was initially created as an open environment with the purpose to serve as a virtual instrument maker workshop. Indeed, the modal formalism offers several interesting advantages, among them the uniform description of numerous mechanical or acoustical systems allowing easy hybridizations. Wildest virtual instruments may well be imagined, played, and manipulated. As there are very few acoustics volumes or mechanical structures tractable by an exact analytical solution, numerical methods, such as FEM, have been programmed for complex geometry for both structures and fluids. The usages are now extending from the virtual reproduction of existing instruments to industrial prototyping. This diversification as the necessity to further improve performance made it necessary to rethink many parts of the software, from the core synthesizer to the numerous interfaces: textual, MAX/MSP, OPENMUSIC, and MATLAB. To control physical modeling synthesis, it is necessary to specify the physical, low-level details of how to play an instrument. Consequently, several recent studies have focused on the study of instrumental gesture and its modeling, thereby increasing the realism of the synthesis. This presentation will review the current possibilities of the software which will be illustrated by examples. Work in progress will also be presented