Spatial Sound: Principles and Applications

Description

Spatial sound is an enhanced and immersive set of audio techniques which provides sound in three-dimensional virtual space. This comprehensive handbook sets out the basic principles and methods with a representative group of applications: sound field and spatial hearing; principles and analytic methods of various spatial sound systems, including two-channel stereophonic sound, and multichannel horizontal and spatial surround sound; ambisonics; wavefield synthesis; binaural playback and virtual auditory display; recording and synthesis, and storage and transmission of spatial sound signals; and objective and subjective evaluation. Applications range from cinemas to small mobile devices. The only book to review spatial sound principles and applications extensively Covers the whole field of spatial sound The book suits researchers, graduate students, and specialist engineers in acoustics, audio, and signal processing. Cover Half Title Title Page Copyright Page Table of Contents Preface Introduction Chapter 1: Sound field, spatial hearing, and sound reproduction 1.1 Spatial coordinate systems 1.2 Sound fields and their physical characteristics 1.2.1 Free-field and sound waves generated by simple sound sources 1.2.2 Reflections from boundaries 1.2.3 Directivity of sound source radiation 1.2.4 Statistical analysis of acoustics in an enclosed space 1.2.5 Principle of sound receivers 1.3 Auditory system and perception 1.3.1 Auditory system and its functions 1.3.2 Hearing threshold and loudness 1.3.3 Masking 1.3.4 Critical band and auditory filter 1.4 Artificial head models and binaural signals 1.4.1 Artificial head models 1.4.2 Binaural signals and head-related transfer functions 1.5 Outline of spatial hearing 1.6 Localization cues for a single sound source 1.6.1 Interaural time difference 1.6.2 Interaural level difference 1.6.3 Cone of confusion and head movement 1.6.4 Spectral cues 1.6.5 Discussion on directional localization cues 1.6.6 Auditory distance perception 1.7 Summing localization and spatial hearing with multiple sources 1.7.1 Summing localization with two sound sources 1.7.2 The precedence effect 1.7.3 Spatial auditory perceptions with partially correlated and uncorrelated source signals 1.7.4 Auditory scene analysis and spatial hearing 1.7.5 Cocktail party effect 1.8 Room reflections and auditory spatial impression 1.8.1 Auditory spatial impression 1.8.2 Sound field-related measures and auditory spatial impression 1.8.3 Binaural-related measures and auditory spatial impression 1.9 Principle, classification, and development of spatial sound 1.9.1 Basic principle of spatial sound 1.9.2 Classification of spatial sound 1.9.3 Developments and applications of spatial sound 1.10 Summary Chapter 2: Two-channel stereophonic sound 2.1 Basic principle of a two-channel stereophonic sound 2.1.1 Interchannel level difference and summing localization equation 2.1.2 Effect of frequency 2.1.3 Effect of interchannel phase difference 2.1.4 Virtual source created by interchannel time difference 2.1.5 Limitation of two-channel stereophonic sound 2.2 Microphone and signal simulation techniques for two-channel stereophonic sound 2.2.1 XY microphone pair 2.2.2 MS transformation and the MS microphone pair 2.2.3 Spaced microphone technique 2.2.4 Near-coincident microphone technique 2.2.5 Spot microphone and pan-pot technique 2.2.6 Discussion on microphone and signal simulation techniques for two-channel stereophonic sound 2.3 Upmixing and downmixing between two-channel stereophonic and mono signals 2.4 Two-channel stereophonic reproduction 2.4.1 Standard loudspeaker configuration of two-channel stereophonic sound 2.4.2 Influence of front-back deviation of the head 2.4.3 Influence of lateral translation of the head and off-center compensation 2.5 Summary Chapter 3: Basic principles and analysis of multichannel surround sound 3.1 Physical and psychoacoustic principles of multichannel surround sound 3.2 Summing localization in multichannel horizontal surround sound 3.2.1 Summing localization equations for multiple horizontal loudspeakers 3.2.2 Analysis of the velocity and energy localization vectors of the superposed sound field 3.2.3 Discussion on horizontal summing localization equations 3.3 Multiple loudspeakers with partly correlated and low-correlated signals 3.4 Summary Chapter 4: Multichannel horizontal surround sound with a regular loudspeaker configuration 4.1 Discrete quadraphone 4.1.1 Outline of the quadraphone 4.1.2 Discrete quadraphone with pair-wise amplitude panning 4.1.3 Discrete quadraphone with the first-order sound field signal mixing 4.1.4 Some discussions on discrete quadraphones 4.2 Other horizontal surround sounds with regular loudspeaker configurations 4.2.1 Six-channel reproduction with pair-wise amplitude panning 4.2.2 The first-order sound field signal mixing and reproduction with M ≥ 3 loudspeakers 4.3 Transformation of horizontal sound field signals and Ambisonics 4.3.1 Transformation of the first-order horizontal sound field signals 4.3.2 The first-order horizontal Ambisonics 4.3.3 The higher-order horizontal Ambisonics 4.3.4 Discussion and implementation of the horizontal Ambisonics 4.4 Summary Chapter 5: Multichannel horizontal surround sound with irregular loudspeaker configuration 5.1 Outline of surround sounds with accompanying picture and general uses 5.2 5.1-Channel surround sound and its signal mixing analysis 5.2.1 Outline of 5.1-channel surround sound 5.2.2 Pair-wise amplitude panning for 5.1-channel surround sound 5.2.3 Global Ambisonic-like signal mixing for 5.1-channel sound 5.2.4 Optimization of three frontal loudspeaker signals and local Ambisonic-like signal mixing 5.2.5 Time panning for 5.1-channel surround sound 5.3 Other multichannel horizontal surround sounds 5.4 Low-frequency effect channel 5.5 Summary Chapter 6: Multichannel spatial surround sound 6.1 Summing localization in multichannel spatial surround sound 6.1.1 Summing localization equations for spatial multiple loudspeaker configurations 6.1.2 Velocity and energy localization vector analysis for multichannel spatial surround sound 6.1.3 Discussion on spatial summing localization equations 6.1.4 Relationship with the horizontal summing localization equations 6.2 Signal mixing methods for a pair of vertical loudspeakers in the median and sagittal plane 6.3 Vector base amplitude panning 6.4 Spatial Ambisonic signal mixing and reproduction 6.4.1 Principle of spatial Ambisonics 6.4.2 Some examples of the first-order spatial Ambisonics 6.4.3 Local Ambisonic-like signal mixing for vertical loudspeaker configuration 6.4.4 Recreating a top virtual source with a horizontal loudspeaker arrangement and Ambisonic signal mixing 6.5 Advanced multichannel spatial surround sounds and problems 6.5.1 Some advanced multichannel spatial surround sound techniques and systems 6.5.2 Object-based spatial sound 6.5.3 Some problems related to multichannel spatial surround sound 6.6 Summary Chapter 7: Microphone and signal simulation techniques for multichannel sound 7.1 Basic considerations on the microphone and signal simulation techniques for multichannel sounds 7.2 Microphone techniques for 5.1-channel sound recording 7.2.1 Outline of microphone techniques for 5.1-channel sound recording 7.2.2 Main microphone techniques for 5.1-channel sound recording 7.2.3 Microphone techniques for the recording of three frontal channels 7.2.4 Microphone techniques for ambience recording and combination with frontal localization information recording 7.2.5 Stereophonic plus center channel recording 7.3 Microphone techniques for other multichannel sounds 7.3.1 Microphone techniques for other discrete multichannel sounds 7.3.2 Microphone techniques for Ambisonic recording 7.4 Simulation of localization signals for multichannel sounds 7.4.1 Methods of the simulation of directional localization signals 7.4.2 Simulation of virtual source distance and extension 7.4.3 Simulation of a moving virtual source 7.5 Simulation of reflections for stereophonic and multichannel sounds 7.5.1 Delay algorithms and discrete reflection simulation 7.5.2 IIR filter algorithm of late reverberation 7.5.3 FIR, hybrid FIR, and recursive filter algorithms of late reverberation 7.5.4 Algorithms of audio signal decorrelation 7.5.5 Simulation of room reflections based on physical measurement and calculation 7.6 Directional audio coding and multichannel sound signal synthesis 7.7 Summary Chapter 8: Matrix surround sound and downmixing/upmixing of multichannel sound signals 8.1 Matrix surround sound 8.1.1 Matrix quadraphone 8.1.2 Dolby Surround system 8.1.3 Dolby Pro-Logic decoding technique 8.1.4 Some developments on matrix surround sound and logic decoding techniques 8.2 Downmixing of multichannel sound signals 8.3 Upmixing of multichannel sound signals 8.3.1 Some considerations in upmixing 8.3.2 Simple upmixing methods for front-channel signals 8.3.3 Simple methods for Ambient component separation 8.3.4 Model and statistical characteristics of two-channel stereophonic signals 8.3.5 A scale-signal-based algorithm for upmixing 8.3.6 Upmixing algorithm based on principal component analysis 8.3.7 Algorithm based on the least mean square error for upmixing 8.3.8 Adaptive normalized algorithm based on the least mean square for upmixing 8.3.9 Some advanced upmixing algorithms 8.4 Summary Chapter 9: Physical analysis of multichannel sound field recording and reconstruction 9.1 Each order approximation of ideal reproduction and Ambisonics 9.1.1 Each order approximation of ideal horizontal reproduction 9.1.2 Each order approximation of ideal three-dimensional reproduction 9.2 General formulation of multichannel sound field reconstruction 9.2.1 General formulation of multichannel sound field reconstruction in the spatial domain 9.2.2 Formulation of spatial-spectral domain analysis of circular secondary source array 9.2.3 Formulation of spatial-spectral domain analysis for a secondary source array on spherical surface 9.3 Spatial-spectral domain analysis and driving signals of Ambisonics 9.3.1 Reconstructed sound field of horizontal Ambisonics 9.3.2 Reconstructed sound field of spatial Ambisonics 9.3.3 Mixed-order Ambisonics 9.3.4 Near-field compensated higher-order Ambisonics 9.3.5 Ambisonic encoding of complex source information 9.3.6 Some special applications of spatial-spectral domain analysis of Ambisonics 9.4 Some problems related to Ambisonics 9.4.1 Secondary source array and stability of Ambisonics 9.4.2 Spatial transformation of Ambisonic sound field 9.5 Error analysis of Ambisonic-reconstructed sound field 9.5.1 Integral error of Ambisonic-reconstructed wavefront 9.5.2 Discrete secondary source array and spatial-spectral aliasing error in Ambisonics 9.6 Multichannel reconstructed sound field analysis in the spatial domain 9.6.1 Basic method for analysis in the spatial domain 9.6.2 Minimizing error in reconstructed sound field and summing localization equation 9.6.3 Multiple receiver position matching method and its relation to the mode-matching method 9.7 Listening room reflection compensation in multichannel sound reproduction 9.8 Microphone array for multichannel sound field signal recording 9.8.1 Circular microphone array for horizontal Ambisonic recording 9.8.2 Spherical microphone array for spatial Ambisonic recording 9.8.3 Discussion on microphone array recording 9.9 Summary Chapter 10: Spatial sound reproduction by wave field synthesis 10.1 Basic principle and implementation of wave field synthesis 10.1.1 Kirchhoff–Helmholtz boundary integral and WFS 10.1.2 Simplification of the types of secondary sources 10.1.3 WFS in a horizontal plane with a linear array of secondary sources 10.1.4 Finite secondary source array and effect of spatial truncation 10.1.5 Discrete secondary source array and spatial aliasing 10.1.6 Some issues and related problems on WFS implementation 10.2 General theory of WFS 10.2.1 Green’s function of Helmholtz equation 10.2.2 General theory of three-dimensional WFS 10.2.3 General theory of two-dimensional WFS 10.2.4 Focused source in WFS 10.3 Analysis of WFS in the spatial-spectral domain 10.3.1 General formulation and analysis of WFS in the spatial-spectral domain 10.3.2 Analysis of the spatial aliasing in WFS 10.3.3 Spatial-spectral division method of WFS 10.4 Further discussion on sound field reconstruction 10.4.1 Comparison among various methods of sound field reconstruction 10.4.2 Further analysis of the relationship between acoustical holography and sound field reconstruction 10.4.3 Further analysis of the relationship between acoustical holography and Ambisonics 10.4.4 Comparison between WFS and Ambisonics 10.5 Equalization of WFS under nonideal conditions 10.6 Summary Chapter 11: Binaural reproduction and virtual auditory display 11.1 Basic principles of binaural reproduction and virtual auditory display 11.1.1 Binaural recording and reproduction 11.1.2 Virtual auditory display 11.2 Acquisition of HRTFs 11.2.1 HRTF measurement 11.2.2 HRTF calculation 11.2.3 HRTF customization 11.3 Basic physical features of HRTFs 11.3.1 Time-domain features of far-field HRIRs 11.3.2 Frequency domain features of far-field HRTFs 11.3.3 Features of near-field HRTFs 11.4 HRTF-based filters for binaural synthesis 11.5 Spatial interpolation and decomposition of HRTFs 11.5.1 Directional interpolation of HRTFs 11.5.2 Spatial basis function decomposition and spatial sampling theorem of HRTFs 11.5.3 HRTF spatial interpolation and signal mixing for multichannel sound 11.5.4 Spectral shape basis function decomposition of HRTFs 11.6 Simplification of signal processing for binaural synthesis 11.6.1 Virtual loudspeaker-based algorithms 11.6.2 Basis function decomposition-based algorithms 11.7 Equalization of the characteristics of headphone-to-ear canal transmission 11.7.1 Principle of headphone equalization 11.7.2 Some problems with binaural reproduction and VAD 11.8 Binaural reproduction through loudspeakers 11.8.1 Basic principle of binaural reproduction through loudspeakers 11.8.2 Virtual source distribution in two-front loudspeaker reproduction 11.8.3 Head movement and stability of virtual sources in Transaural reproduction 11.8.4 Timbre coloration and equalization in transaural reproduction 11.9 Virtual reproduction of stereophonic and multichannel surround sound 11.9.1 Binaural reproduction of stereophonic and multichannel sound through headphones 11.9.2 Stereophonic expansion and enhancement 11.9.3 Virtual reproduction of multichannel sound through loudspeakers 11.10 Rendering system for dynamic and real-time virtual auditory environments 11.10.1 Binaural room modeling 11.10.2 Dynamic virtual auditory environments system 11.11 Summary Chapter 12: Binaural pressures and auditory model analysis of spatial sound reproduction 12.1 Physical analysis of binaural pressures in summing virtual source and auditory events 12.1.1 Evaluation of binaural pressures and localization cues 12.1.2 Method for summing localization analysis 12.1.3 Binaural pressure analysis of stereophonic and multichannel sound with amplitude panning 12.1.4 Analysis of summing localization with interchannel time difference 12.1.5 Analysis of summing localization at the off-central listening position 12.1.6 Analysis of interchannel correlation and spatial auditory sensations 12.2 Binaural auditory models and analysis of spatial sound reproduction 12.2.1 Analysis of lateral localization by using auditory models 12.2.2 Analysis of front-back and vertical localization by using a binaural auditory model 12.2.3 Binaural loudness models and analysis of the timbre of spatial sound reproduction 12.3 Binaural measurement system for assessing spatial sound reproduction 12.4 Summary Chapter 13: Storage and transmission of spatial sound signals 13.1 Analog audio storage and transmission 13.1.1 45°/45° Disk recording system 13.1.2 Analog magnetic tape audio recorder 13.1.3 Analog stereo broadcasting 13.2 Basic concepts of digital audio storage and transmission 13.3 Quantization noise and shaping 13.3.1 Signal-to-quantization noise ratio 13.3.2 Quantization noise shaping and 1-Bit DSD coding 13.4 Basic principle of digital audio compression and coding 13.4.1 Outline of digital audio compression and coding 13.4.2 Adaptive differential pulse-code modulation 13.4.3 Perceptual audio coding in the time-frequency domain 13.4.4 Vector quantization 13.4.5 Spatial audio coding 13.4.6 Spectral band replication 13.4.7 Entropy coding 13.4.8 Object-based audio coding 13.5 MPEG series of audio coding techniques and standards 13.5.1 MPEG-1 audio coding technique 13.5.2 MPEG-2 BC audio coding 13.5.3 MPEG-2 advanced audio coding 13.5.4 MPEG-4 audio coding 13.5.5 MPEG parametric coding of multichannel sound and unified speech and audio coding 13.5.6 MPEG-H 3D audio 13.6 Dolby series of coding techniques 13.6.1 Dolby digital coding technique 13.6.2 Some advanced Dolby coding techniques 13.7 DTS series of coding technique 13.8 MLP lossless coding technique 13.9 ATRAC technique 13.10 Audio video coding standard 13.11 Optical disks for audio storage 13.11.1 Structure, principle, and classification of optical disks 13.11.2 CD family and its audio formats 13.11.3 DVD family and its audio formats 13.11.4 SACD and its audio formats 13.11.5 BD and its audio formats 13.12 Digital radio and television broadcasting 13.12.1 Outline of digital radio and television broadcasting 13.12.2 Eureka-147 digital audio broadcasting 13.12.3 Digital radio mondiale 13.12.4 In-band on-channel digital audio broadcasting 13.12.5 Audio for digital television 13.13 Audio storage and transmission by personal computer 13.14 Summary Chapter 14: Acoustic conditions and requirements for the subjective assessment and monitoring of spatial sound 14.1 Outline of acoustic conditions and requirements for spatial sound intended for domestic reproduction 14.2 Acoustic consideration and design of listening rooms 14.3 Arrangement and characteristics of loudspeakers 14.3.1 Arrangement of the main loudspeakers in listening rooms 14.3.2 Characteristics of the main loudspeakers 14.3.3 Bass management and arrangement of subwoofers 14.4 Signal and listening level alignment 14.5 Standards and guidance for conditions of spatial sound reproduction 14.6 Headphones and binaural monitors of spatial sound reproduction 14.7 Acoustic conditions for cinema sound reproduction and monitoring 14.8 Summary Chapter 15: Psychoacoustic and subjective assessment experiments on spatial sound 15.1 Outline of psychoacoustic and subjective assessment experiments 15.2 Contents and attributes for spatial sound assessment 15.3 Auditory comparison and discrimination experiment 15.3.1 Paradigms of auditory comparison and discrimination experiment 15.3.2 Examples of auditory comparison and discrimination experiment 15.4 Subjective assessment of small impairments in spatial sound systems 15.5 Subjective assessment of a spatial sound system with intermediate quality 15.6 Virtual source localization experiment 15.6.1 Basic methods for virtual source localization experiments 15.6.2 Preliminary analysis of the results of virtual source localization experiments 15.6.3 Some results of virtual source localization experiments 15.7 Summary Chapter 16: Applications of spatial sound and related problems 16.1 Applications to commercial cinema, domestic reproduction, and automotive audio 16.1.1 Application to commercial cinema and related problems 16.1.2 Applications to domestic reproduction and related problems 16.1.3 Applications to automobile audio 16.2 Applications to virtual reality, communications, multimedia, and mobile devices 16.2.1 Applications to virtual reality 16.2.2 Applications to communication and information systems 16.2.3 Applications to multimedia 16.2.4 Applications to mobile and handheld devices 16.3 Applications to the scientific experiments of spatial hearing and psychoacoustics 16.4 Applications to sound field auralization 16.4.1 Auralization in room acoustics 16.4.2 Other applications of auralization technique 16.5 Applications to clinical medicine 16.6 Summary Appendix A: Spherical harmonic functions Appendix B: Some statistical methods for the data of psychoacoustic and subjective assessment experiments References Index