Acoustique | EPFL Graph Search

L’acoustique est la science du son. La discipline a étendu son domaine à l'étude de toute onde mécanique dans tout fluide, où un ébranlement se propage presque exclusivement en onde longitudinale ; le calcul de ces ondes selon les caractéristiques du milieu s'applique aussi bien pour l'air aux fréquences audibles que pour tout milieu fluide homogène et toute fréquence, y compris infrasons et ultrasons. On parle de vibroacoustique quand l'étude se porte sur l'interaction entre solides, où existent des ondes transversales, et fluides. L'acoustique comprend de nombreuses ramifications comme l'électroacoustique (microphones, haut-parleurs), l’acoustique musicale, l'acoustique architecturale. L'acoustique a des applications dans les domaines des sciences de la terre et de l'atmosphère, des sciences de l'ingénieur, des sciences de la vie et de la santé. Histoire Les études sur ce qu'on appelle acoustique depuis Joseph Sauveur remontent à l'Antiquité. Pythagore étudie au l'

Integrating Real-Time Room Acoustics Simulation into a CAD Modeling Software to Enhance the Architectural Design Process

Dirk Schröder

For architects, real-time 3D visual rendering of CAD-models is a valuable tool. The architect usually perceives the visual appearance of the building interior in a natural and realistic way during the design process. Unfortunately this only emphasizes the role of the visual appearance of a building, while the acoustics often remain disregarded. Controlling the room acoustics is not integrated into most architects’ workflows—due to a lack of tools. The present contribution describes a newly developed plug-in for adding an adequate 3D-acoustics feedback to the architect. To present intuitively the acoustical effect of the current design project, the plug-in uses real-time audio rendering and 3D-reproduction. The room acoustics of the design can be varied by modifying structural shapes as well as by changing the material selection. In addition to the audio feedback, also a visualization of important room acoustics qualities is provided by displaying color-coded maps inside the CAD software.

2014

Measurement and characterization of room impulse responses

Thomas Batschelet

Room acoustics refers to the audio capture of an enclosed room. It can be seen as its color and fully describes the characteristics of the room, including the shape, size or the population. The goal of the project is to set up a database of Room impulse responses which will be useful in many fields in order to test algorithms. This document covers the way to set up equipment and successfully capture one of those room impulse responses.

2016

De l'acoustique des églises en Suisse

Victor Desarnaulds

The existence of the fundamental conflict in churches between the desirable acoustic conditions for music and for speech intelligibility prompted this dissertation. It tackles the subject not only under the acoustical perspective but also in the historical, theological, musicological and architectural aspects. This research studies, initially, how during the past, the liturgy, the acoustical and organizational characteristics of churches supported one or the other of these attributes. The second chapter presents the objective analyses of many Reformed worships and Catholic masses which make it possible to show the conditions and requirements for the current Christian celebrations in Switzerland. The analysis of the church geometrical parameters (volume, height, etc.) and of the results of objective acoustical measurements (reverberation time, background noise and speech intelligibility) of approximately two hundred churches in Switzerland allows to statistically describe their characteristics and to objectively verify the assumptions made in the preceding chapter. Chapter 3 also studies the local or global range of conclusions by the comparison of the results obtained in Switzerland with those published for other countries (synthesis of about 400 churches). The study of the origin and the interaction between Liturgy and Acoustics passes in particular by the analysis of the history of sacred music but especially by the examination of the main methods implemented to improve the acoustics of churches. Chapter 4 presents the historical evolution and the acoustical effectiveness of two types of devices used in churches: acoustic pots and pulpits with their canopies. The position of the various participants does not influence only the listening conditions but also reveals the importance attached to their participation. Chapter 5 examines then the historical evolution and statistical analysis of the current conditions regarding the position of the organ, the spatial arrangements for the seated congregation in churches, as well as the effect of the occupation on reverberation time and speech intelligibility. Chapter 6 concludes with the analysis of the desirable acoustical conditions in current churches, particularly with regard to the architectural, organizational (sound system, assembly arrangement and organ location) and the acoustical parameters (reverberation time, background noise and speech intelligibility). This last analysis is based on a significant bibliographical synthesis and on the comparison, for the sampled churches, of the results for objective measurements with the subjective evaluations obtained by a parishioner's sample survey.

EPFL2002

De l'acoustique des églises en Suisse

Victor Desarnaulds

EPFL2002