Architectural Acoustics Illustrated

APPLY THE PRINCIPLES OF DESIGN TO THE SCIENCE OF SOUND

RECIPIENT OF THE VIRGINIA SOCIETY AMERICAN INSTITUTE OF ARCHITECTS 2014 PRIZE FOR SCHOLARSHIP AND DESIGN RESEARCH

Architectural Acoustics Illustrated translates the quantitative and qualitative content of acoustics into the graphic language of architecture. Important to performance space design as well as surface material selection, room shaping and sizing, building placement and orientation, building skin and barrier composition, space planning, and architectural detailing building acoustics begins at the earliest stages of schematic design and continues through construction administration. Better building acoustics makes better buildings and architectural acoustics needn′t be a mystery.

This highly visual guide includes over 350 illustrations that outline the physics of sound and the established methods of mitigating unwanted noise in buildings. With authoritative guidance on the latest materials and techniques, topics include a summary checklist of acoustic design guidelines. The Companion website offers video animations that help readers to:

Understand the fundamental behaviors and movements of sound, including sound level, propagation, and frequencySelect building surfaces with sound absorption (or reflection) in mindDesign to make music fuller and speech clearerReduce unwanted noise from both within the room and from outside the roomMaster the calculations that direct acoustic design solutions

All design professionals should have a clear understanding of how sound and space interact, and Architectural Acoustics Illustrated is a comprehensive, practical guide designed for the visual learner.

Acknowledgments xi

Introduction xiii

1. Basic Theory 1

Sound Level 2

Sound Level 2

Source Path Receiver 4

Measuring Sound Level 5

Measuring Sound Level 8

Multiple Sound Sources 9

Decibel Addition 10

Sound Propagation 11

Sound Propagation 11

Directivity 12

Sound Frequency 13

Frequency 13

Octave Bands 17

Sound Level Perception and Frequency 19

A ]Weighted Decibels 20

The Special Case of Low ]Frequency Sound 22

2. Sound Absorption 25

Principles of Absorptive and Reflective Surfaces 26

Absorption Coefficient 27

Types of Sound Absorbers 29

Room Constant 33

Room Average Absorption 33

Noise Reduction Coefficient (NRC) 36

Sound Absorption Data 38

3. Room Acoustics 57

Room Acoustics Qualities 58

Impulse Response 58

Reverberance 60

Optimal Reverberation Time 65

Clarity 66

Variable Acoustics 70

Reverberation Time Calculation Checklist 74

Room Shaping for Speech and Music 75

Loudness 76

Balconies 80

Sightlines 82

Warmth 83

Concert Hall Types 85

Spatial Impression 87

Intimacy 94

Diffusion 95

Theater Planning 97

Stage Acoustics 97

Orchestra Pits 101

What Makes a Good Room for Music? 102

Performance Venue Seats 106

Acoustic Defects 109

Acoustic Defects 109

Performance Venues 114

Room Acoustics History 114

Performance Venues to Visit 117

Design Checklists 118

Rooms for Unamplified Music Performance Checklist 118

Other Types of Rooms Checklist 119

Sound System Design 123

Electronic Sound Reinforcement 123

4. Noise Control  131

Sound Isolation Principles 132

Apartment Layout Graphic Quiz 132

Flanking 133

Flanking Graphic Checklist 134

Flanking Noise Checklist 134

Measures of Airborne Sound Isolation 140

Transmission Loss (TL) 140

Sound Transmission Class (STC) 142

How to Measure Sound Transmission Class (STC) 144

Target STC Ratings 146

Noise Reduction (NR) 147

Achieving Higher Acoustical Privacy 148

Background Noise 152

Background Noise 152

Noise Criteria (NC) 153

Speech Intelligibility and Noise 155

Open ]Plan Office Acoustics 157

Sound Transmission Loss Data 162

Noise Reduction Example Problem 175

Air ]Structure ]Air Flanking 178

Acoustic Privacy Checklist 179

Apartment Layout Quiz Answer 180

Door and Window Sound Isolation 182

Doors 182

Noise Isolation and Windows 184

Impact Noise 185

Impact Noise Isolation 185

How to Measure IIC 190

Impact Noise Checklist 192

Recommended Floor ]Ceiling Assemblies 195

Resiliently Mounted Room Surfaces 197

Community Noise 202

Principles of Community Noise 202

Building ]in ]Building Design 202

Noise Sources 204

Community Noise Research 207

Community Noise Example Problem 208

Outdoor Barriers 209

Outdoor Barriers Checklist 210

Outdoor Barrier Example Problem 212

Wind Turbine Noise 214

Community Noise Checklist 215

Mechanical System Noise 217

Principles of Mechanical System Noise 217

Ducted Fan Noise 220

Mechanical Room Graphic Checklist 224

Ducted Air Turbulence Noise 225

Vibration Isolation 229

Mechanical Noise Checklist 232

Plumbing Noise 237

Isolating Pipes from Structure 238

Plumbing Noise Checklist 239

index 243

MICHAEL ERMANN is an associate professor at Virginia Tech′s School of Architecture + Design, and a past undergraduate architecture program co–chairman. He teaches architectural acoustics, design studio, and environmental building systems. Prior to joining the VT faculty, Professor Ermann was an acoustical consultant at Artec in New York, NY and Siebein Associates in Gainesville, FL.