Designing Sound

I
Theory
5
2
Theory Introduction
7
3
Physical Sound
9
3.1
Elementary Physics
9
Energy
9
Force
9
Pressure
9
Work
10
Systems
10
Power
10
Energy Sources
10
Matter and Mass
11
Force, Distance, and Acceleration
11
Displacement, Movement, and Freedom
12
Excitation
12
3.2
Materials
12
Elasticity and Restoration
13
Density
15
Plasticity
16
Structure and Strength
17
3.3
Waves
17
Wave Models
17
Exchange of Forces
18
Propagation
19
Wave Types
20
Amplitude
20
Speed
21
Group and Phase Velocity
22
Wavelength
23
Frequency and Period
23
Simple Wave Math
23

---

Phase
24
Superposition and Phase Cancellation
24
3.4
Boundaries
25
Phase of Bending Waves at Solid Boundaries
26
Coupling
28
Reflection and Standing Waves
28
Modes
29
Visualising Sound Waves
30
Shape
30
Entropy and Heat
31
Loss and Damping
31
3.5
Analogues
32
Potential
32
Energy Inlet
33
Flow
33
Resistance
33
Tap or Outlet
34
Capacitance
34
Example Network Analogy
35
Example System Analysis
36
Acknowledgements
37
References
37
4
Oscillations
39
4.1
Oscillators
39
Period and Frequency
39
Frequency of a Spinning Object
39
Relaxation
41
Frequency of Relaxation Systems
42
Quantisation
43
4.2
Simple Harmonic Oscillators
43
Frequency of a Mass on Spring
44
Frequency of a Pendulum
46
Frequency of an LC Network
46
4.3
Complex Harmonic Oscillators
48
Oscillation of a String
48
Oscillation of a Bar or Rod
49
Oscillation of Cones, Membranes, Laminas
50
4.4
Driven Oscillations and Resonance
51
References
53
5
Acoustics
55
5.1
Acoustic Systems
55
Vibrations in Air
55
Radiation
56

---

Radiation Patterns
56
Spherical, Cylindrical, and Planar Waves
57
5.2
Intensity and Attenuation
58
Sound Pressure Level
58
Position and Correlation
58
Acoustic Sound Intensity
59
Geometric Attenuation
60
Transmission and Absorption
61
5.3
Other Propagation Effects
62
Reflection
62
Scattering
62
Dispersion
63
Refraction
63
Diffraction
64
Diffusion
65
Ground Effects
66
Oblique Boundary Loss
66
Wind Shear
67
Aberration
67
The Doppler Effect
67
Room Acoustics
67
Reverb Time
68
Outdoor Acoustics
70
5.4
Acoustic Oscillations
70
Turbulence
70
Reynolds Number
71
Sounds of Turbulence
71
Pipes
71
Radiation from Pipes and Horns
73
Helmholtz Oscillator
73
Textbooks
74
Papers
74
Online Resources
74
6
Psychoacoustics
77
6.1
Perceiving Sounds
77
Ears
77
Frequency Range of Human Hearing
78
Nonlinearity
78
Threshold of Hearing
78
Just Noticeable Difference
79
Localisation
79
Interaural Time Difference
79
Interaural Intensity Difference
80
Head Response Transfer Function
80
Distance
80

---

Source Identity
81
Perception of Loudness
81
Loudness Scales and Weighting
81
Duration and Loudness
82
Fatigue
83
Change of Loudness
83
Perception of Frequency
83
Pure Tone Discrimination
83
Critical Bands
83
Ranges
84
Resolution
85
Average of Close Components
85
Rapid Change of Amplitude
85
Phantom Fundamentals
86
Huggins Binaural Pitch
86
Bilsen Band Edge Pitch
86
Perception of Spectra
86
Perception of Harmonic and Inharmonic Spectra
87
Consonance, Harmony, and Roughness
87
Brightness, Dullness, and Spectral Centroid
88
Resonance, Flatness, and Formants
88
Perception of Temporal Structure
88
Granularity
89
Events and Flows
89
Envelopes
89
Attack
89
Transient and Rise Time
90
Slow Attacks
90
Decay
90
Sustain
90
Release
91
Effort and Movement
91
Precedence and Belonging
91
Gabor Limit for Duration
91
Hirsh Limit for Ordering
91
Streaming
92
Streaming by Pitch
92
Van Noorden Ambiguity
92
Spectral and Spacial Streams
92
6.2
Sound Cognition
93
Gestalt Effects
93
Discrimination
93
Scaling
94
Similarity
94
Matching
95

---

Classification
95
Identification
95
Recognition
95
Attention
96
Correspondence
96
Asynchronous Sound
96
Acousmatic Sound
97
The Audiovisual Contract
97
Absence
97
Concurrent Masking
98
Temporal Proximity Masking
98
6.3
Auditory Scene Analysis
99
Segregation
99
Schema Activation
100
Primitive Features
100
Harmonicity
100
Continuity
101
Momentum
101
Monotonicity
101
Temporal Correlation
102
Coherence
102
The Process of Scene Analysis
102
6.4
Auditory Memory
103
Short- and Long-term Memory
103
Auditory Pipeline
103
Verbal and Nonverbal Memory
103
Visual Augmentation
104
6.5
Listening Strategies
104
Listening Hierarchy
104
Reflexive
104
Connotative
105
Causal
105
Empathetic
105
Functional
105
Semantic
106
Critical
106
Reduced
106
Analytic Listening
106
Component Analysis
106
Signal Listening
107
Engaged
107
6.6
Physiological Responses to Sound
108
Stapedius Reflex
108
Startle Response
108
Orientation Response
108

---

Ecstatic Response
108
Stress Responses
109
Binaural Beat Entrainment
109
Psychotherapeutical Applications and Art
109
Cross-modal Perception
110
6.7
Sound, Language, and Knowledge
110
Imagining Sound
110
Talking about Sound
111
Noun Descriptions
111
Adjective and Adjunctive Descriptions
111
Gerund Verb Descriptions
111
Onomatopoeia and Alliteration
112
Reference Points
112
Procedural Knowledge
112
Declarative Domain Knowledge
112
Imperative Knowledge
113
Poetic Knowledge
113
Categorical Knowledge
113
Weak Cultural Domain Knowledge
113
Strong Cultural Domain Knowledge
113
Exercises
114
Exercise 1—Perception
114
Exercise 2—Language
114
Exercise 3—Knowledge and Communication
114
Acknowledgements
114
References
114
Books
114
Papers
115
Online Resources
117
7
Digital Signals
119
7.1
Signals
119
Transducers
119
Electronic, Continuous Signals
119
Sound Transducers
119
Information
119
Representing Signals
120
Digital Encoding
121
Digital-to-Analog Conversion
121
Analog-to-Digital Conversion
122
Digital Signal Processing
123
Floating Point Normalised Form
123
Smoothing Samples
124
7.2
Graphs
125
Spectra
125

---

Spectrograms
126
Waterfall Plots
127
7.3
Generating Digital Waveforms
128
Generating Samples
128
Buffering
128
The Sound of Zero (Silence)
129
The Sound of One (Constants)
129
Moving Signals
131
Sinusoidal Waves
132
Complex Harmonic Motion
134
Randomly Moving Signals
136
Suddenly Moving Signals
137
Slowly Moving Signals
139
Signal Programming Abstraction
141
A Csound Snippet
142
A CLM Snippet
142
Acknowledgements
143
References
143
Books
143
Papers
143
Online Resources
144
II
Tools
145
8
Tools Introduction
147
8.1
What You Will Need
147
8.2
Tools for Sound Design
147
8.3
Supporting Tools
148
9
Starting with Pure Data
149
9.1
Pure Data
149
Installing and Running Pure Data
150
Testing Pure Data
150
9.2
How Does Pure Data Work?
151
Objects
152
Connections
152
Data
152
Patches
152
A Deeper Look at Pd
153
Pure Data Software Architecture
153
Your First Patch
153
Creating a Canvas
155
New Object Placement
155
Edit Mode and Wiring
155

---

Initial Parameters
156
Modifying Objects
156
Number Input and Output
156
Toggling Edit Mode
156
More Edit Operations
157
Patch Files
157
9.3
Message Data and GUI Boxes
157
Selectors
158
Bang Message
158
Bang Box
158
Float Messages
158
Number Box
159
Toggle Box
159
Sliders and Other Numerical GUI Elements
159
General Messages
160
Message Box
160
Symbolic Messages
160
Symbol Box
161
Lists
161
Pointers
161
Tables, Arrays, and Graphs
161
9.4
Getting Help with Pure Data
162
Exercises
163
Exercise 1
163
Exercise 2
163
Exercise 3
163
References
163
10
Using Pure Data
165
10.1
Basic Objects and Principles of Operation
165
Hot and Cold Inlets
165
Bad Evaluation Order
165
Trigger Objects
166
Making Cold Inlets Hot
166
Float Objects
166
Int Objects
167
Symbol and List Objects
167
Merging Message Connections
167
10.2
Working with Time and Events
167
Metronome
167
A Counter Timebase
168
Time Objects
168
Select
169
10.3
Data Flow Control
169
Route
169

---

Moses
170
Spigot
170
Swap
170
Change
170
Send and Receive Objects
171
Broadcast Messages
171
Special Message Destinations
171
Message Sequences
171
10.4
List Objects and Operations
172
Packing and Unpacking Lists
172
Substitutions
173
Persistence
173
List Distribution
173
More Advanced List Operations
174
10.5
Input and Output
174
The Print Object
175
MIDI
175
10.6
Working with Numbers
177
Arithmetic Objects
177
Trigonometric Maths Objects
178
Random Numbers
178
Arithmetic Example
178
Comparative Objects
178
Boolean Logical Objects
178
10.7
Common Idioms
179
Constrained Counting
179
Accumulator
179
Rounding
180
Scaling
180
Looping with Until
180
Message Complement and Inverse
181
Random Selection
182
Weighted Random Selection
182
Delay Cascade
182
Last Float and Averages
182
Running Maximum (or Minimum)
183
Float Low Pass
183
11
Pure Data Audio
185
11.1
Audio Objects
185
Audio Connections
185
Blocks
185
Audio Object CPU Use
185
11.2
Audio Objects and Principles
186
Fanout and Merging
186

---

Time and Resolution
187
Audio Signal Block to Messages
187
Sending and Receiving Audio Signals
187
Audio Generators
187
Audio Line Objects
189
Audio Input and Output
189
Example: A Simple MIDI Monosynth
189
Audio Filter Objects
190
Audio Arithmetic Objects
191
Trigonometric and Math Objects
191
Audio Delay Objects
191
References
192
12
Abstraction
193
12.1
Subpatches
193
Copying Subpatches
194
Deep Subpatches
194
Abstractions
195
Scope and $0
196
12.2
Instantiation
196
12.3
Editing
197
12.4
Parameters
197
12.5
Defaults and States
198
12.6
Common Abstraction Techniques
199
Graph on Parent
199
Using List Inputs
200
Packing and Unpacking
200
Control Normalisation
201
Summation Chains
202
Routed Inputs
203
13
Shaping Sound
205
13.1
Amplitude-Dependent Signal Shaping
205
Simple Signal Arithmetic
205
Limits
207
Wave Shaping
207
Squaring and Roots
209
Curved Envelopes
210
13.2
Periodic Functions
211
Wrapping Ranges
211
Cosine Function
211
13.3
Other Functions
212
Polynomials
212
Expressions
213

---

13.4
Time-Dependent Signal Shaping
213
Delay
214
Phase Cancellation
214
Filters
215
User-Friendly Filters
215
Integration
215
Differentiation
217
References
217
14
Pure Data Essentials
219
14.1
Channel Strip
219
Signal Switch
219
Simple Level Control
219
Using a Log Law Fader
220
MIDI Fader
220
Mute Button and Smooth Fades
221
Panning
221
Simple Linear Panner
221
Square Root Panner
222
Cosine Panner
222
Crossfader
224
Demultiplexer
224
14.2
Audio File Tools
225
Monophonic Sampler
225
File Recorder
226
Loop Player
227
14.3
Events and Sequencing
227
Timebase
227
Select Sequencer
228