Search results for "Sound"
showing 10 items of 1845 documents
Handcrafting in archaeomusicological research
2016
There were no conference proceedings but you may find video recordings of some of the talks by following the link above; International audience; Archaeological flutes, as sound artefacts, both stand in material and immaterial culture. They are made of tremendous subtleties that archaeologists have a hard time to understand while these are craftsmen's everyday life. These subtleties are the link between material (rough material, tools, gestures) and immaterial (sounds, music, timber, uses) issues. They are the reason why archaeology cannot study ancient sound instruments on its own. A one-year insight experience of apprenticeship alongside a traditional-flute-maker (Jean-Daniel Talma, ElBock…
Compte rendu de : Basile Zimmermann, Waves and Forms. Electronic Devices and Computer Encoding in China, Cambridge, The MIT Press, 2015, 296 p.
2018
International audience
The Electric Guitar as a Sound Generator in Rock Music (1954-2014)
2005
International audience
Recent developments in the acoustical properties of perforated and porous materials containing dead-end pores
2017
It was shown recently in Nevers, France, Sherbrooke, Canada and Salford, UK, that porous materials with semi-opened pores or materials with open pores bearing lateral cavities or resonators at the microscopic scale of the pores can result in peculiar sound absorption properties. Various examples of these materials can be found in engineering and in everyday life including bio-based materials. The cavities and resonators can be assimilated to dead-end pores, which are opened at one end and closed at the other. The dead-end pores are known to geophysicists. We studied them more recently in the field of engineering acoustics where the saturating fluid is air. The closed ends prevent the fluid …
Acoustical properties of air-saturated porous material with periodically distributed dead-end pores
2015
International audience; A theoretical and numerical study of the sound propagation in air-saturated porous media with straight main pores bearing lateral cavities (dead-ends) is presented. The lateral cavities are located at " nodes " periodically spaced along each main pore. The effect of periodicity in the distribution of the lateral cavities is studied, and the low frequency limit valid for the closely spaced dead-ends is considered separately. It is shown that the absorption coefficient and transmission loss are influenced by the viscous and thermal losses in the main pores as well as their perforation rate. The presence of long or short dead-ends significantly alters the acoustical pro…
Holes Interaction Effects under high and medium Sound Intensities for Micro-perforated panels design
2010
International audience; Most models for predicting the acoustic response of perforated panels are based on the assumption that there are no interactions between the holes. This paper investigates the Hole Interaction Effect (HIE) and distribution effect on the sound absorption coefficient of perforated panels when submitted to medium and high sound pressure levels. It is experimentally demonstrated that though the HIE is mostly an added mass effect, the nonlinear resistance parameters depend on the separation distance between the apertures. Analysis of the data reveals the fact that even with HIE, the nonlinear reactance dependency with velocity is very low compared to the resistance-veloci…
Acoustic properties of plates with unevenly distributed macro perforations backed by woven meshes
2012
A hybrid model describing the acoustic properties of plates with macro-perforations that can be unevenly distributed on the plate surface and backed by woven or precision woven meshes with microscopic perforations is proposed. The plate perforations may be of circular or rectangular shapes. Since the perforated plate may not necessarily be considered as an equivalent fluid, its surface impedance is calculated by the Maa model [Noise Control Eng. J. 29, 77-84 (1987)], whereas the Johnson-Champoux-Allard model [J. Appl. Phys. 70, 1975-1979 (1991)] is used for the mesh. It is observed that the absorption of the carrying plate seems to depend on the hydraulic diameter of the perforations and no…
On the measurement and prediction of the sound absorption coefficient of air-cavity backed perforated plates considering the holes interaction effect…
2012
International audience; This paper deals with the measurement and prediction of air cavity backed perforated plates considering the holes interaction effect under relatively low sound excitation. A revised expression for the radiation contribution is proposed to properly account for the holes interaction effect. This expression is integrated in the characteristic impedance expression following Atalla and Sgard [J. Sound Vib. 303, 195-208 (2007)] model. Perforated plate specimens with different centre-to-centre holes distances (pitches) are built and tested using an impedance tube. The particular cases of holes interaction effect with constant low porosity and of holes interaction effect wit…
Sound absorption coefficient of a porous material covered with a low open area perforated plate under high sound excitation
2012
International audience; The sound absorption coefficient of porous materials covered with low open area perforated plate is studied under high sound intensities in the absence of mean flow. The theoretical considerations are based on the equivalent fluid following the Johnson-Champoux-Allard approach and the use of the transfer matrix method. To take into account the high sound levels effects, the air flow resistivity of each layer is modified following the Forchheimer law. Two specimens of perforated plate are built and tested when backed by a polymeric foam and a fibrous material. A specific impedance tube setup is developed for the measurement of the surface acoustic impedance for sound …
TRANS-FUSIMO – A novel system for treatment support for FUS applications in moving abdominal organs
2018
Computer based treatemnt support for FUS therapy of moviving abdominal organs is essential due to great intrinsic challenges: the target moves due to breathing and may be occluded by the rib cage. In the EU project TRANS-FUSIMO we have developed a sophisticated software system that connects to a FUS transducer and an MRI. This enables physicians to conduct safe, effective and efficient ablation of tumors in the moving liver.