Room Acoustics

by Heinrich Kuttruff, Michael Vorländer

Overview

This thoroughly revised and long awaited new edition of a classic text builds on the success of the 1991 third edition. Kuttruf considers the theory and practice of sound behavior in closed spaces; a key area for acoustical engineers worldwide. It is of particular interest to those working on auditoria and will therefore stand as an excellent complement to Barron's Auditorium Acoustics. This new edition includes important new material on the growth of digital technology and sound intensity.

Product Details

ISBN-13:	9781032478258
Publisher:	CRC Press
Publication date:	07/24/2024
Edition description:	7th ed.
Pages:	344
Product dimensions:	7.00(w) x 10.00(h) x 0.00(d)

About the Author

Heinrich Kuttruff is Emeritus Professor and former head of the Institute of Technical Acoustics at Aachen University, Germany.

Table of Contents

List of symbols ix

Preface xiii

Acknowledgments xv

Introduction xvii

1 Some facts on sound waves, sources and hearing 1

1.1 Basic relations - The wave equation 1

1.2 Plane waves and spherical waves 3

1.3 Energy density and intensity, radiation 7

1.4 Signals and systems 9

1.5 Sound pressure level and sound power level 14

1.6 Some properties of human hearing 15

1.7 Sound sources 18

References 22

2 Reflection and scattering 23

2.1 Reflection factor, absorption coefficient and wall impedance 23

2.2 Reflection of plane waves 25

2.3 A few examples 30

2.4 Reflection of spherical waves 36

2.5 Random sound incidence 38

2.6 Reflection from finite-sized plane surfaces 42

2.7 Scattering by boundary irregularities 45

References 50

3 Sound waves in a room 51

3.1 Formal solution of the wave equation 52

3.2 Normal modes in a rectangular room with rigid boundaries 54

3.3 Number and density of eigenfrequencies 58

3.4 Non-rigid walls 60

3.5 Numerical solution of the wave equation: The finite element method 63

3.6 Steady-state sound field 66

3.7 Some properties of room transfer functions 70

3.8 Decaying modes, reverberation 75

References 78

4 Geometrical room acoustics 81

4.1 Enclosures with plane walls, image sources 81

4.2 The temporal distribution of reflections 86

4.3 The directional distribution of reflections, diffuse sound field 90

4.4 Enclosures with curved walls 92

4.5 Radiosity integral 95

4.6 Modifications and generalizations, diffusion equation 99

References 102

5 Reverberation and steady-state energy density 103

5.1 Diffuse sound fields, elementary theory of sound decay 104

5.2 Factors influencing sound field diffuseness 106

5.3 Mean free path length and average rate of reflections 108

5.4 Non-uniform boundary absorption 111

5.5 The influence of unequal path lengths 114

5.6 Enclosure driven by a sound source 116

5.7 Applications of the radiosity integral: The influence of imperfect diffuseness 120

References 124

6 Sound absorption and sound absorbers 125

6.1 Energy losses in the medium 125

6.2 Sound absorption by membranes and perforated sheets 128

6.3 Resonance absorbers 131

6.4 Helmholtz resonators 134

6.5 Sound propagation in porous materials, the Rayleigh model 137

6.6 Porous absorbers 141

6.7 Audience and seat absorption 146

6.8 Anechoic rooms 151

References 154

7 Subjective room acoustics 157

7.1 Sound pressure level, strength factor 158

7.2 Some general remarks on reflections and echoes 159

7.3 The perception of reflections and echoes 160

7.4 Echoes and colouration 163

7.5 Parameters characterizing the "early energy" 168

7.5.1 Definition 168

7.5.2 Clarity index 169

7.5.3 Centre time 170

7.5.4 Speech transmission index 171

7.5.5 Support 173

7.6 Reverberation and reverberance 174

7.7 Spaciousness of sound fields 180

7.8 Assessment of concert hall acoustics 182

References 190

8 Measuring techniques in room acoustics 193

8.1 General remarks on instrumentation 193

8.2 Measurement of the impulse response 196

8.3 Examination of the impulse response 201

8.4 Measurement of reverberation 207

8.5 Directional distribution, diffuseness of a sound field 211

8.6 Sound absorption - Tube methods 218

8.7 Sound absorption - Reverberation chamber 221

8.8 Scattering coefficient 225

References 228

9 Design considerations and design procedures 231

9.1 Prediction of noise level 232

9.2 Direct sound 236

9.3 Examination of room shape 238

9.4 Reverberation time 243

9.5 More on concert halls 247

9.6 Multipurpose halls 250

9.7 Acoustical scale models 252

9.8 Computer simulation 254

9.9 Auralization, virtual reality 260

References 265

10 Elcctroacoustical systems in rooms 267

10.1 Loudspeakers 268

10.2 Required power and reach of a loudspeaker 272

10.3 Remarks on loudspeaker positions 275

10.4 Acoustical feedback and its suppression 278

10.5 Reverberation enhancement with external reverberators 283

10.6 Reverberation enhancement by controlled feedback 289

References 293

Index 295

Editorial Reviews

"Room Acoustics remains a classic which should continue to find a place on the shelf of many acousticians."

— David Thompson in Journal of Sound and Vibration

"In its sixth edition, this book remains an indispensable guide for students and practitioners of acoustics. It presents first principles in depth while also being concise, with great supporting diagrams. An easy-to-use reference and go-to resource, particularly for the practitioner looking to relate complex real-world findings back to fundamental theory.

—Raj Patel, Arup Acoustics, USA

"An extremely elegant textbook that covers the engineering aspects of room acoustics. I recommend it to anyone wanting a sound technical introduction into room acoustics, without spending too much time on perception."

—Jean-Dominique Polac, Université Pierre et Marie Curie, Paris

"An unavoidable reference for any serious work in the field of room acoustics."

— Jens Rindel in Nuntius

"The author covers sound waves, sound production, and the mechanics of hearing; the reflection and scattering of sound; the behavior of sound waves in a room; geometrical room acoustics; reverberation and steady-state energy density, sound absorption and sound absorbers, and many other related subjects."

— Eithne O'Leyne, Editor, ProtoView

"Overall, this edition provides valuable new material to keep this classic text up-to-date. If your work or studies involves room acoustics, this book should be your first port of call."

— Neil Thompson Shade in Noise Control Engr. J

"This book in its sixth edition will still receive its readership across many generations of architectural acousticians, graduate students, scientists in acoustics, and beyond"

— Ning Xiang, Graduate Program in Architectural Acoustics, Rensselaer Polytechnic Institute

"...an excellent and concise source for most of the e

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