Computational Acoustics in Architecture: (v. 8. Advances in Architecture)

The scientific discipline known as Architectural Acoustics is only a century old, its origins founded in the studies of Wallace C. Sabine, who designed the acoustic conditioning of the Boston Music Hall (now the Boston Symphony Hall). Following these early investigations considerable further research has been carried out, thus providing a solid scientific base from which to approach this difficult subject. In recent years progress has been further accelerated both by highly sophisticated electronic instruments able to take acoustic measurements in situ, and by powerful computer programs capable of simulating the behaviour of the sound field inside a room with a high degree of precision. This book contains a significant amount of state-of-the-art knowledge on room acoustics. Presented in six chapters, it is written by authors or work teams, all of whom are internationally acknowledged researchers in this scientific-artistic-technical field. The first two chapters centre on the most outstanding aspects of room acoustics studied in depth this century, namely absorption, sound reflection and diffusion, and echo and reverberation.Much current research is dedicated to perfecting models that analyse the so-called subjective attributes of sound fields, and the following sections present studies of simulation models of the binaural experience of listeners in a room. Finally, there are two examinations of recent work carried out on acoustics in concert halls and auditoria, and churches - specific spaces which share the common factor of having been historically "the places of music".

Table of Contents:
Chapter 1 - Reverberation and diffusion: Introduction; Sound rays, echoes and reverberation; Chaotic interference of sound waves; Sound enhancement and artificial reverberation; Subjective preferences; Sound diffusion; Conclusion. Chapter 2 - Sound absorbing materials and sound absorbers in enclosures: Introduction; Absorption of sound and absorption coefficients; Sound absorption in enclosures; Relationship between sound absorption and acoustic parameters in the enclosure; Sound absorbing materials and sound absorbers; Active sound absorbers; Measurements of sound absorption coefficients; Sabine sound absorption coefficients for some common building materials and furnishings. Chapter 3 - 3-D Sound and auralization: Introduction; Basics of localization; Auralization; Overview; Theory; Perception. Chapter 4 - Fundamental subjective attributes of sound fields based on the model of auditory-brain system: Model; Theory for pitch, loudness and timbre; Spatial subjective attributes in relation to spatial factors extracted from the inter-aural cross-correlation function; Subjective attributes in relation to temporal factors extracted from the autocorrelation function of sound signals; Calculations of speech intelligibility of each single syllable in relation to the four orthogonal factors extracted from the ACF of both source and sound-field signals; Appendix: Orthogonal factors of sound fields. Chapter 5 - The sound field for listeners in concert halls and auditoria: Introduction; Sound levels in halls; Spatial impression in halls; Conclusions. Chapter 6 - Acoustics in churches: Introduction; The acoustics of different types of churches; The sound field in Mudejar-Gothic churches with timber roofs; Three acoustic rehabilitation projects in churches.