Journal of the Acoustical Society of America, Oct 1, 2020
To study the effect of 'warming up' a wind instrument, the acoustic impedance spectrum at the mou... more To study the effect of 'warming up' a wind instrument, the acoustic impedance spectrum at the mouthpiece of a trombone was measured after different durations of playing. When an instrument filled with ambient air is played in a room at 26-27 °C, the resonance frequencies initially fall. This is attributed to ! in the breath initially increasing the density of air in the bore and more than compensating for increased temperature and humidity. Soon after, the resonance frequencies rise to near or slightly above the ambient value as the effects of temperature and humidity compensate for that of increased !. The magnitudes and quality factors of impedance maxima decrease with increasing playing time whereas the minima increase. Using the measured change in resonance frequency, it proved possible to separate the changes in impedance due to changes in density and changes in acoustic losses due to water condensing in the bore. When the room and instrument temperature exceed 37 °C, condensation is not expected and, experimentally, smaller decreases in magnitudes and quality factors of impedance maxima are observed. The substantial compensation of the pitch fall due to ! by the rise due to temperature and humidity is advantageous to wind players.
INTER-NOISE and NOISE-CON Congress and Conference Proceedings
While light, temperature and humidity on cultural heritage objects are drastically controlled to ... more While light, temperature and humidity on cultural heritage objects are drastically controlled to assure their better conservation, it is not the case of the vibrations and their impact on the objects have received little consideration. Most of the proposed solutions to protect objects from vibrations suffer from a lack of adaptability and poor performances in the lowest frequency range. To tackle this issue, the development of a new kind of protection devices based on active control is proposed. The main challenge is to respect the cultural heritage ethics: non intrusiveness and reversibility. To adapt to a wide variety of cultural heritage objects, the proposed solution aims to minimize the vibrations of a museum's shelf in real time. A replica of museum's shelf is excited by a vibration exciter and a feedforward control configuration is used to monitor the shelf vibrations, by a reference signal measured on the shelf structure and actuators and error sensors placed on the ...
HAL (Le Centre pour la Communication Scientifique Directe), Oct 1, 2018
Musical instruments can be considered objects that have been empirically optimized for centuries.... more Musical instruments can be considered objects that have been empirically optimized for centuries. Depending on geography and epoch, these optimizations have followed or boosted the evolution of music itself, as instrument-making choices, playing techniques and sound aesthetics are greatly intertwined. For preservation reasons, most of the musical instruments kept in public collections (e.g., in museums) are no longer played. In order to bring these sounds from the past back to life, facsimiles are made by contemporary makers through the study of cultural heritage instruments and their documentation (archives, paintings). Nevertheless, being able to copy an instrument does not mean being able to understand the original meaning and purpose of the instrument. In particular, some material or assembly choices and instrument-maker adjustments are not really known and, using the sample instrument, we have to infer this knowledge. A mechanical and acoustical approach applied to cultural heritage objects allows us to extract objective information by non-invasive means: in situ measurements, observations, modelling. This paper is a step towards a better understanding of the choices made by instrument-makers of the past. The multidisciplinary methodology used here (mixing acoustics, history, organology and perception) allows us to go beyond limitations due to classical descriptive approaches. The paper presents studies about plucked and woodwind instruments as separate sections, as these two instrument families exhibit different technical aspects and instrument-making decisions. As an example of the methodologies used, we consider the voicing of harpsichord plectra and the wood species of woodwind instruments.
HAL (Le Centre pour la Communication Scientifique Directe), Apr 11, 2022
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Viscothermal acoustic propagation in gases contained in rigid straight or conical tubes is consid... more Viscothermal acoustic propagation in gases contained in rigid straight or conical tubes is considered. Under the assumption that the wavelength is much larger than both the boundary layer thickness and the tube radius, pressure and flow are shown to be solutions of a pair of coupled 1D differential equations, formulated as transmission line equations involving complex loss coefficients. The derivation of these loss coefficients, which is usually accomplished in cylinders, is generalized here to conical geometries. In the well-kown case of circular cylinders, the Zwikker-Kosten (ZK) theory is recovered. For circular cones, the expression of the loss coefficients is derived. It involves complex-order spherical harmonics, instead of Bessel functions for circular cylinders, and makes the hydraulic radius appear as a natural relevant geometrical parameter. We show that replacing the classical radius by the hydraulic radius in the ZK theory provides an affordable and accurate approximation of the analytic model derived for cones. The proposed formulas are used to compute the input impedance of a cone, and compared with a 3D reference. In an ideal setting, using the spherical harmonics or the hydraulic radius in the 1D method accurately approximates the full 3D method, and allows to increase accuracy by approximately two orders of magnitude compared to the ZK theory.
In order to simulate the Ondes Martenot, a classic electronic musical instrument, we aim to model... more In order to simulate the Ondes Martenot, a classic electronic musical instrument, we aim to model its circuit using Port-Hamiltonian Systems (PHS). PHS have proven to be a powerful formalism to provide models of analog electronic circuits for audio applications, as they guarantee the stability of simulations, even in the case of non-linear systems. However, some systems cannot be converted directly into PHS because their architecture cause what are called realizability conflicts. The Ondes Martenot circuit is one of those systems. In this paper, a method is introduced to resolve such conflicts automatically: problematic components are replaced by equivalent components without altering the overall structure nor the content of the modeled physical system.
Four advanced trombonists and three beginners played the note B♭2 (the lowest normal note played ... more Four advanced trombonists and three beginners played the note B♭2 (the lowest normal note played with the slide retracted), then ‘lipped up and down’. The normal playing frequency lies above that of the bore impedance peak, so the bore is a compliant load. However, the range reached while lipping is approximately centered on this peak. To investigate how the lip oscillation is regenerated with inertive or compliant acoustic loads, acoustic pressure and flow waveforms were determined both upand downstream from the lips, while playing. The lip opening area and the flow component due to the lips’ sweeping motion were also estimated using a transparent mouthpiece and high-speed video. The lips move forward before separating, then backward before closing. Consequently, the acoustic flow into the mouthpiece becomes positive before the lips open. Further, the volume V of air swept by the lips in the direction of the flow is positive around one cycle. A model in which the lips execute out-o...
In the laboratory of Musée de la Musique, Paris, a part of research activities aims to provide ac... more In the laboratory of Musée de la Musique, Paris, a part of research activities aims to provide acoustical information on collections. Concerning wind instruments, various wood species are used in the making procedure, having undergone different treatment techniques and showing various wearing and aging conditions. Such differences involve large variations of roughness and porosity, affecting the acoustic dissipation in the resonator, with a potential impact on playability and sound. The influence of polishing and oiling on the acoustic dissipation is experimentally investigated with a corpus of five cylindrical pipes, manufactured by a flute maker. Their species are typically used in wind instrument making: maple (Acer Pseudoplatanus), pear wood (Pyrus Communis L.), boxwood (Buxus Sempervirens) and African Blackwood (Dalbergia Melanoxylon). The pipes are parallel to the grain, except one whose axis forms an angle of 60 degrees relative to the fiber direction. A simple method is sugg...
A phylogenetic tree is a visual representation of the evolutionary relationships linking organism... more A phylogenetic tree is a visual representation of the evolutionary relationships linking organisms or species, analogous to a genealogy for members of a family. In phylogenetic trees, nodes represent ancestors, leaves represent species, and edges represent time or the amount of character or genetic change. The visualization and the comparison of such hierarchical structure can be very challenging, especially when the number of species is high. In this work, we suggest a new approach for getting insights into the main structural features of phylogenetic trees. We define simple rules for the sonification of a phylogeny and apply them to the simplified tree of Boroeutheria, a group of mammals comprising, among others, human, mouse, rabbit, whale and cat. This approach appears to be very promising for better apprehending tree structures.
In the low and medium range, the playability of woodwind instruments depends on the resonance cha... more In the low and medium range, the playability of woodwind instruments depends on the resonance characteristics of the air column. These characteristics are related to the surface condition of the bore. They are determined by the wood species and the direction of the cutting line, and are modified by several immersions in oil during and after the making process. The input impedances of pipes made of maple with different surface conditions are measured. One immersion in oil significantly increases the quality factors and the amplitudes of the first twelve bore resonances. When the wood fiber is not parallel to the trunk direction, the porosity of the pipe is higher, and a second immersion in oil increases these characteristics to a bigger extent. For the pipes with a fiber parallel to the trunk and immersed twice in oil, the input impedance is similar to that of a model of rigid pipe. 22 ème Congrès Français de Mécanique Lyon, 24 au 28 Août 2015 Mots clefs : instruments de musique à ve...
Some of the authors of this publication are also working on these related projects: Farémi "Faire... more Some of the authors of this publication are also working on these related projects: Farémi "Faire parler les instruments de musique du patrimoine" View project Building a facsimile of an Érard grand piano of 1802 View project
By applying active control to an oscillator, its modal behaviour changes. This paper makes a comp... more By applying active control to an oscillator, its modal behaviour changes. This paper makes a comparison between a second order damped harmonic oscillator and a xylophone bar's mode. Then it proposes a method for acting on an eigen resonance of a xylo- phone bar. The purpose is to get sound modifications, by bringing under quantitative and independent control its pitch
The Journal of the Acoustical Society of America, 2008
The physical parameters of a violin bridge have a significant influence on the tonal colouration ... more The physical parameters of a violin bridge have a significant influence on the tonal colouration of its sound. The resonance peaks of the bridge shape the response of the violin body. Reinicke and Cremer developed a simple bridge model that shows a typical broad frequency peak around 2.5kHz, because it incorporates the coupling to the violin body and the soundpost. By using the same model, Jim Woodhouse revealed the effect of some parameters of the bridge (mass, stiffness and foot spacing) on the instrument frequency response. Here the parameters of the violin resonance peaks are changed in real time, by applying an active control method. Such a technique, very useful in noise reduction, enabled to change separately the position and the shape of each peak of the bridge input admittance. On the bridge, 2 actuators and an accelerometer are placed at strategic positions in order to change the peak frequency and the damping factor values. The system behaviour is controlled by a Digital ...
As imple active control method is described which extends the possibilities of ax ylophone bar.I ... more As imple active control method is described which extends the possibilities of ax ylophone bar.I ta llows the performer to modify the vibration of its structure, unlikepost-processing effects involving loudspeakers. These variations change the characteristics of the partials radiated by the bar.T he xylophone bar,m ade of composite material, is equipped with twoactuators and one sensor in PVDF (polyvinylidene fluoride), the mass and stiffness of which do not modify the mechanical characteristics. Ac ontroller in af eedback loop is executed on am idrange digital signal processor.I ti sc omposed of as um of second order band-pass filters. The selection of the controller coefficients relies on the measured transfer function between the input of the controller and the output of the sensor.F irst the active control method is designed to modify the resonance peaks of as imple model of ax ylophone bar,w hose transfer function is as uperposition of three eigenmodes. Then it is applied to the real system. It is illustrated by increasing and reducing the amplitudes and/or frequencies of the first resonances, and by modifying the tuning of the xylophone bar.
Journal of the Acoustical Society of America, Oct 1, 2020
To study the effect of 'warming up' a wind instrument, the acoustic impedance spectrum at the mou... more To study the effect of 'warming up' a wind instrument, the acoustic impedance spectrum at the mouthpiece of a trombone was measured after different durations of playing. When an instrument filled with ambient air is played in a room at 26-27 °C, the resonance frequencies initially fall. This is attributed to ! in the breath initially increasing the density of air in the bore and more than compensating for increased temperature and humidity. Soon after, the resonance frequencies rise to near or slightly above the ambient value as the effects of temperature and humidity compensate for that of increased !. The magnitudes and quality factors of impedance maxima decrease with increasing playing time whereas the minima increase. Using the measured change in resonance frequency, it proved possible to separate the changes in impedance due to changes in density and changes in acoustic losses due to water condensing in the bore. When the room and instrument temperature exceed 37 °C, condensation is not expected and, experimentally, smaller decreases in magnitudes and quality factors of impedance maxima are observed. The substantial compensation of the pitch fall due to ! by the rise due to temperature and humidity is advantageous to wind players.
INTER-NOISE and NOISE-CON Congress and Conference Proceedings
While light, temperature and humidity on cultural heritage objects are drastically controlled to ... more While light, temperature and humidity on cultural heritage objects are drastically controlled to assure their better conservation, it is not the case of the vibrations and their impact on the objects have received little consideration. Most of the proposed solutions to protect objects from vibrations suffer from a lack of adaptability and poor performances in the lowest frequency range. To tackle this issue, the development of a new kind of protection devices based on active control is proposed. The main challenge is to respect the cultural heritage ethics: non intrusiveness and reversibility. To adapt to a wide variety of cultural heritage objects, the proposed solution aims to minimize the vibrations of a museum's shelf in real time. A replica of museum's shelf is excited by a vibration exciter and a feedforward control configuration is used to monitor the shelf vibrations, by a reference signal measured on the shelf structure and actuators and error sensors placed on the ...
HAL (Le Centre pour la Communication Scientifique Directe), Oct 1, 2018
Musical instruments can be considered objects that have been empirically optimized for centuries.... more Musical instruments can be considered objects that have been empirically optimized for centuries. Depending on geography and epoch, these optimizations have followed or boosted the evolution of music itself, as instrument-making choices, playing techniques and sound aesthetics are greatly intertwined. For preservation reasons, most of the musical instruments kept in public collections (e.g., in museums) are no longer played. In order to bring these sounds from the past back to life, facsimiles are made by contemporary makers through the study of cultural heritage instruments and their documentation (archives, paintings). Nevertheless, being able to copy an instrument does not mean being able to understand the original meaning and purpose of the instrument. In particular, some material or assembly choices and instrument-maker adjustments are not really known and, using the sample instrument, we have to infer this knowledge. A mechanical and acoustical approach applied to cultural heritage objects allows us to extract objective information by non-invasive means: in situ measurements, observations, modelling. This paper is a step towards a better understanding of the choices made by instrument-makers of the past. The multidisciplinary methodology used here (mixing acoustics, history, organology and perception) allows us to go beyond limitations due to classical descriptive approaches. The paper presents studies about plucked and woodwind instruments as separate sections, as these two instrument families exhibit different technical aspects and instrument-making decisions. As an example of the methodologies used, we consider the voicing of harpsichord plectra and the wood species of woodwind instruments.
HAL (Le Centre pour la Communication Scientifique Directe), Apr 11, 2022
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Viscothermal acoustic propagation in gases contained in rigid straight or conical tubes is consid... more Viscothermal acoustic propagation in gases contained in rigid straight or conical tubes is considered. Under the assumption that the wavelength is much larger than both the boundary layer thickness and the tube radius, pressure and flow are shown to be solutions of a pair of coupled 1D differential equations, formulated as transmission line equations involving complex loss coefficients. The derivation of these loss coefficients, which is usually accomplished in cylinders, is generalized here to conical geometries. In the well-kown case of circular cylinders, the Zwikker-Kosten (ZK) theory is recovered. For circular cones, the expression of the loss coefficients is derived. It involves complex-order spherical harmonics, instead of Bessel functions for circular cylinders, and makes the hydraulic radius appear as a natural relevant geometrical parameter. We show that replacing the classical radius by the hydraulic radius in the ZK theory provides an affordable and accurate approximation of the analytic model derived for cones. The proposed formulas are used to compute the input impedance of a cone, and compared with a 3D reference. In an ideal setting, using the spherical harmonics or the hydraulic radius in the 1D method accurately approximates the full 3D method, and allows to increase accuracy by approximately two orders of magnitude compared to the ZK theory.
In order to simulate the Ondes Martenot, a classic electronic musical instrument, we aim to model... more In order to simulate the Ondes Martenot, a classic electronic musical instrument, we aim to model its circuit using Port-Hamiltonian Systems (PHS). PHS have proven to be a powerful formalism to provide models of analog electronic circuits for audio applications, as they guarantee the stability of simulations, even in the case of non-linear systems. However, some systems cannot be converted directly into PHS because their architecture cause what are called realizability conflicts. The Ondes Martenot circuit is one of those systems. In this paper, a method is introduced to resolve such conflicts automatically: problematic components are replaced by equivalent components without altering the overall structure nor the content of the modeled physical system.
Four advanced trombonists and three beginners played the note B♭2 (the lowest normal note played ... more Four advanced trombonists and three beginners played the note B♭2 (the lowest normal note played with the slide retracted), then ‘lipped up and down’. The normal playing frequency lies above that of the bore impedance peak, so the bore is a compliant load. However, the range reached while lipping is approximately centered on this peak. To investigate how the lip oscillation is regenerated with inertive or compliant acoustic loads, acoustic pressure and flow waveforms were determined both upand downstream from the lips, while playing. The lip opening area and the flow component due to the lips’ sweeping motion were also estimated using a transparent mouthpiece and high-speed video. The lips move forward before separating, then backward before closing. Consequently, the acoustic flow into the mouthpiece becomes positive before the lips open. Further, the volume V of air swept by the lips in the direction of the flow is positive around one cycle. A model in which the lips execute out-o...
In the laboratory of Musée de la Musique, Paris, a part of research activities aims to provide ac... more In the laboratory of Musée de la Musique, Paris, a part of research activities aims to provide acoustical information on collections. Concerning wind instruments, various wood species are used in the making procedure, having undergone different treatment techniques and showing various wearing and aging conditions. Such differences involve large variations of roughness and porosity, affecting the acoustic dissipation in the resonator, with a potential impact on playability and sound. The influence of polishing and oiling on the acoustic dissipation is experimentally investigated with a corpus of five cylindrical pipes, manufactured by a flute maker. Their species are typically used in wind instrument making: maple (Acer Pseudoplatanus), pear wood (Pyrus Communis L.), boxwood (Buxus Sempervirens) and African Blackwood (Dalbergia Melanoxylon). The pipes are parallel to the grain, except one whose axis forms an angle of 60 degrees relative to the fiber direction. A simple method is sugg...
A phylogenetic tree is a visual representation of the evolutionary relationships linking organism... more A phylogenetic tree is a visual representation of the evolutionary relationships linking organisms or species, analogous to a genealogy for members of a family. In phylogenetic trees, nodes represent ancestors, leaves represent species, and edges represent time or the amount of character or genetic change. The visualization and the comparison of such hierarchical structure can be very challenging, especially when the number of species is high. In this work, we suggest a new approach for getting insights into the main structural features of phylogenetic trees. We define simple rules for the sonification of a phylogeny and apply them to the simplified tree of Boroeutheria, a group of mammals comprising, among others, human, mouse, rabbit, whale and cat. This approach appears to be very promising for better apprehending tree structures.
In the low and medium range, the playability of woodwind instruments depends on the resonance cha... more In the low and medium range, the playability of woodwind instruments depends on the resonance characteristics of the air column. These characteristics are related to the surface condition of the bore. They are determined by the wood species and the direction of the cutting line, and are modified by several immersions in oil during and after the making process. The input impedances of pipes made of maple with different surface conditions are measured. One immersion in oil significantly increases the quality factors and the amplitudes of the first twelve bore resonances. When the wood fiber is not parallel to the trunk direction, the porosity of the pipe is higher, and a second immersion in oil increases these characteristics to a bigger extent. For the pipes with a fiber parallel to the trunk and immersed twice in oil, the input impedance is similar to that of a model of rigid pipe. 22 ème Congrès Français de Mécanique Lyon, 24 au 28 Août 2015 Mots clefs : instruments de musique à ve...
Some of the authors of this publication are also working on these related projects: Farémi "Faire... more Some of the authors of this publication are also working on these related projects: Farémi "Faire parler les instruments de musique du patrimoine" View project Building a facsimile of an Érard grand piano of 1802 View project
By applying active control to an oscillator, its modal behaviour changes. This paper makes a comp... more By applying active control to an oscillator, its modal behaviour changes. This paper makes a comparison between a second order damped harmonic oscillator and a xylophone bar's mode. Then it proposes a method for acting on an eigen resonance of a xylo- phone bar. The purpose is to get sound modifications, by bringing under quantitative and independent control its pitch
The Journal of the Acoustical Society of America, 2008
The physical parameters of a violin bridge have a significant influence on the tonal colouration ... more The physical parameters of a violin bridge have a significant influence on the tonal colouration of its sound. The resonance peaks of the bridge shape the response of the violin body. Reinicke and Cremer developed a simple bridge model that shows a typical broad frequency peak around 2.5kHz, because it incorporates the coupling to the violin body and the soundpost. By using the same model, Jim Woodhouse revealed the effect of some parameters of the bridge (mass, stiffness and foot spacing) on the instrument frequency response. Here the parameters of the violin resonance peaks are changed in real time, by applying an active control method. Such a technique, very useful in noise reduction, enabled to change separately the position and the shape of each peak of the bridge input admittance. On the bridge, 2 actuators and an accelerometer are placed at strategic positions in order to change the peak frequency and the damping factor values. The system behaviour is controlled by a Digital ...
As imple active control method is described which extends the possibilities of ax ylophone bar.I ... more As imple active control method is described which extends the possibilities of ax ylophone bar.I ta llows the performer to modify the vibration of its structure, unlikepost-processing effects involving loudspeakers. These variations change the characteristics of the partials radiated by the bar.T he xylophone bar,m ade of composite material, is equipped with twoactuators and one sensor in PVDF (polyvinylidene fluoride), the mass and stiffness of which do not modify the mechanical characteristics. Ac ontroller in af eedback loop is executed on am idrange digital signal processor.I ti sc omposed of as um of second order band-pass filters. The selection of the controller coefficients relies on the measured transfer function between the input of the controller and the output of the sensor.F irst the active control method is designed to modify the resonance peaks of as imple model of ax ylophone bar,w hose transfer function is as uperposition of three eigenmodes. Then it is applied to the real system. It is illustrated by increasing and reducing the amplitudes and/or frequencies of the first resonances, and by modifying the tuning of the xylophone bar.
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