Binaural Hearing: With 93 Illustrations (Springer Handbook of Auditory Research, 73)

The field of Binaural Hearing involves studies of auditory perception, physiology, and modeling, including normal and abnormal aspects of the system. Binaural processes involved in both sound localization and speech unmasking have gained a broader interest and have received growing attention in the published literature. The field has undergone some significant changes. There is now a much richer understanding of the many aspects that comprising binaural processing, its role in development, and in success and limitations of hearing-aid and cochlear-implant users. The goal of this volume is to provide an up-to-date reference on the developments and novel ideas in the field of binaural hearing. The primary readership for the volume is expected to be academic specialists in the diverse fields that connect with psychoacoustics, neuroscience, engineering, psychology, audiology, and cochlear implants. This volume will serve as an important resource by way of introduction to the field, in particular for graduate students, postdoctoral scholars, the faculty who train them and clinicians. The Acoustical Society of America Series Preface Preface 1992 Volume Preface Contents Contributors Chapter 1: Binaural Processing of Sounds 1.1 Introduction 1.1.1 The Roles of Binaural Hearing 1.1.2 The Importance of Binaural Hearing 1.1.3 Physiological Substrate of Binaural Hearing 1.2 Definition of Critical Concepts and Processing of Binaural Cues 1.3 Spatial Unmasking and the Effects of Rooms 1.4 Relationship Between Perception, Physiology, and Modeling 1.5 Aging and Hearing Impairment 1.6 Concluding Remarks References Chapter 2: Localization and Lateralization of Sound 2.1 Introduction 2.2 Interaural Differences 2.2.1 Airhead Model 2.2.2 Woodworth Model 2.2.3 Spherical-Head Model 2.2.3.1 Interaural Time Difference 2.2.3.2 Interaural Level Difference 2.2.4 Cones of Confusion and Coordinate Systems 2.2.4.1 Spherical-Polar System 2.2.4.2 Lateral-Polar System 2.2.4.3 Solving for Lateral and Polar Angles 2.2.4.4 Solving for Azimuth and Elevation 2.3 Interaural Sensitivity 2.3.1 Interaural Phase Difference 2.3.2 Lateralization 2.3.3 Externalization 2.3.4 Interaural Time Difference Encoding 2.3.5 Duplex Theory 2.3.6 Opponent-Hemifield Model 2.4 Precedence Effect 2.4.1 Precedence Attributes 2.4.1.1 Fusion 2.4.1.2 Localization Dominance 2.4.1.3 Lag Discrimination Suppression 2.4.2 Modeling the Precedence Effect 2.4.3 The Central Precedence Effect 2.4.3.1 Stimulus Type 2.4.3.2 Development 2.4.3.3 Breakdown and Buildup 2.4.3.4 Franssen Illusion 2.4.3.5 Median Sagittal Plane 2.4.3.6 Back to the Periphery 2.4.4 Ongoing Precedence Effect 2.5 Summary References Chapter 3: Sound Source Localization Is a Multisystem Process 3.1 Introduction 3.2 A Brief History of Sound Source Localization (1825–1942) 3.3 Wallach’s Multisystem Proposal for Sound Source Localization 3.4 Auditory-Spatial Cues 3.4.1 Sound Source Localization in Azimuth 3.4.2 Sound Source Localization in Elevation 3.4.3 Cones of Confusion 3.4.4 Sound Source Localization in Distance/Range 3.5 Head-Position Cues in Sound Source Localization 3.5.1 Visual Head-Position Cues 3.5.2 Vestibular Head-Position Cues 3.5.3 Proprioceptive Head-Position Cues 3.5.4 Other Possible Head-Position Cues 3.6 Sound Source Localization as the Integration of Head-Position and Auditory-Spatial Cues 3.6.1 Head Rotation Resolves Front-Back Reversals 3.6.2 The 2:1 Rotation Scenario and the Wallach Azimuth Illusion 3.6.3 Studies of the Wallach Azimuth Illusion 3.6.4 Wallach Elevation Illusion 3.6.5 Other Studies of the Integration of Head-Position and Auditory-Spatial Cues in Sound Source Localization 3.7 Studies of Sound Source Localization When Head-Position or Auditory-Spatial Cues May Be Degraded 3.7.1 Auditory-Spatial Cue Degradation 3.7.2 Head-Position Cue Degradation 3.8 Additional Observations Concerning the Integration of Auditory-Spatial and Head-Position Cues 3.9 Summary References Chapter 4: Anatomy and Physiology of the Avian Binaural System 4.1 Introduction 4.2 Acoustics of Binaural Hearing 4.3 Neural Coding of Monaural Phase and Amplitude 4.4 Computation of Interaural Time Difference and Interaural Level Difference 4.5 Neural Basis of Spatial Acuity 4.6 Sound Localization in Complex Acoustical Environments 4.6.1 Does the Delay of the Echo Really Determine Echo Threshold? 4.6.2 Are Echoes Suppressed? 4.6.3 A Simpler Explanation of Localization Dominance? 4.6.4 Generalizing the Envelope Hypothesis 4.7 Concluding Remarks References Chapter 5: Binaural Hearing by the Mammalian Auditory Brainstem: Joint Coding of Interaural Level and Time Differences by the Lateral Superior Olive 5.1 Introduction 5.2 The Acoustical Cues to Sound Source Location 5.2.1 Interaural Level Differences 5.2.2 Interaural Time Differences: Fine Structure, Envelope, and Transient 5.3 Neural Processing of Sound Localization Cues in the Auditory Brainstem 5.3.1 Coding of Interaural Level Differences in the Lateral Superior Olive 5.3.2 Coding of Interaural Time Differences in the Lateral Superior Olive 5.3.2.1 Coding of Fine-Structure Interaural Time Differences 5.3.2.1.1 Coding of Low-Frequency Fine-Structure Interaural Time Differences in the Medial Superior Olive 5.3.2.2 Coding of Envelope Interaural Time Differences 5.3.2.3 Coding of Transient Interaural Time Differences 5.4 Features of the Lateral Superior Olive Circuitry Favor Detection of Interaural Time Differences 5.4.1 Precisely Timed Glycinergic Inhibition Shapes Processing of Interaural Time Differences 5.5 The Binaural Interaction Component of the Auditory Brainstem Response: A Noninvasive Window into Binaural Brainstem Function 5.6 Summary References Chapter 6: Binaural Hearing with Temporally Complex Signals 6.1 Introduction 6.1.1 Taxonomy and Terminology of Binaural Cues 6.2 Binaural Sensitivity Declines at High Rates of Envelope Fluctuation 6.3 Temporal Weighting Reveals Binaural Dominance of Onset-Like Events 6.3.1 Evidence of Rate-Dependent Onset Dominance in the Temporal Weighting of ITDenv Cues at High Frequency 6.3.2 Evidence of Rate-Dependent Emphasis of Interaural Level Difference Cues Near Onset and Offset 6.3.3 Evidence of Onset Dominance in the Temporal Weighting of Low-Frequency Interaural Time Difference Fine Structure Cues 6.3.4 Evidence Against Onset Dominance for “Noise” 6.4 Envelope Fluctuations Improve Sensitivity to Ongoing Cues 6.4.1 Binaural “Readout” Window 6.4.2 Binaural “Restarting” 6.4.3 Temporal Jitter 6.4.4 Implications for Access to Ongoing Cues in Noise 6.5 Evidence That Envelope Shape Influences Sensitivity to Binaural Cues 6.6 Evidence for Sensitivity to Binaural Cues Conveyed by Interaurally Decorrelated Signals 6.7 Sensitivity to Interaural Correlation in Binaural Detection Tasks 6.8 Accounting for the Effects of Envelopes on Binaural Hearing: RESTART Theory 6.8.1 Sampling of Binaural Cues During Rising-Envelope Events 6.8.2 Rate Limitation of Binaural Sampling 6.8.3 Reduced Sensitivity to Ongoing Cues in Steady-State Sounds 6.8.4 Independent Binaural Sampling Across Frequency Bands 6.9 Summary and Conclusions 6.9.1 Implications and Applications for Real-World Listening References Chapter 7: Binaural Hearing and Across-Channel Processing 7.1 Introduction 7.2 Integration Across Frequency for Binaural Discrimination and Lateralization 7.2.1 Increasing the Bandwidth of a Noise 7.2.2 Increasing the Number of Components in a Complex 7.2.3 Across-Frequency Weighting of Interaural Time Difference and Interaural Level Difference 7.2.4 Binaural Fusion 7.3 Effect of Conflicting Binaural Cues Across Frequency 7.3.1 Multiple Sound Sources 7.3.2 Studies of Across-Frequency Binaural Interference 7.3.3 The Role of Grouping in Across-Frequency Binaural Interference 7.4 Models of Binaural Integration of Localization Information 7.4.1 Overview 7.4.2 Cross-Correlation Models for Interaural Time Difference 7.4.3 Intensity-Weighted Cross-Correlation Models 7.4.4 Across-Frequency Processing of Interaural Time Difference 7.4.5 Modeling Interaural Level Difference-Based Lateralization 7.4.6 Accounting for Multiple Simultaneous Sources 7.4.7 Modeling Localization in Complex Environments 7.5 Summary References Chapter 8: Binaural Unmasking and Spatial Release from Masking 8.1 Binaural Unmasking 8.1.1 Basic Phenomena and Terminology 8.1.2 Underlying Cues 8.1.3 Narrowband Unmasking and Across-Frequency Binaural Interference 8.1.4 Modeling Binaural Unmasking 8.1.5 Binaural Unmasking of Speech 8.2 Spatial Release from Masking and Speech Intelligibility 8.2.1 Stationary Noise Interferers 8.2.2 Models of Spatial Release from Masking in Stationary Noise 8.2.3 Modulated Noise Interferers 8.2.4 Speech Interferers 8.2.5 Reverberation 8.3 Summary References Chapter 9: Spatial Hearing in Rooms and Effects of Reverberation 9.1 Introduction 9.2 Acoustical Aspects 9.2.1 The Impulse Response of a Room 9.2.2 Common Room Acoustic Measures that Can be Derived from the Room Impulse Response and Binaural Room Impulse Response 9.2.2.1 Reverberation Time 9.2.2.2 Relative Reverberation Energy 9.2.2.3 Sound Strength 9.2.2.4 Spatial Impression 9.2.2.5 Timbre/Tone Color 9.2.2.6 Speech Intelligibility 9.3 Psychoacoustical Aspects 9.3.1 Listener Sensitivity to Room Acoustics 9.3.1.1 Effects of a Single Reflection and the Precedence Effect 9.3.1.2 Audibility of Multiple Reflections 9.3.1.3 Differential Sensitivity to Room Acoustic Measures 9.3.2 Objective Effects of Room Acoustics on Listening Performance 9.3.2.1 Directional Sound Localization 9.3.2.2 Distance Localization and Externalization 9.3.2.3 Speech Intelligibility 9.3.2.3.1 Temporal Distortion and Validation of the Speech Transmission Index 9.3.2.3.2 Effect of Background Noise 9.3.2.3.3 Binaural and Spatial Effects 9.3.2.3.4 Effects of Hearing Loss and Age 9.3.2.3.5 Adaptation Effects 9.3.3 Subjective Effects of Room Acoustics 9.3.3.1 Loudness 9.3.3.2 Spatial Impression 9.3.3.3 Timbre 9.3.3.4 Effects of Hearing Loss 9.4 Summary References Chapter 10: Computational Models of Binaural Processing 10.1 Introduction 10.1.1 Purpose of Modeling 10.1.2 Auditory Modeling 10.2 Signal and System Theory Applied to Binaural Interaction 10.2.1 Peripheral Filtering and Binaural Coherence 10.2.2 Extraction of Interaural Time Difference 10.3 Modeling Physiological Data 10.3.1 Background 10.3.1.1 Binaural Pathways 10.3.1.2 Classification of Physiological Models 10.3.2 Medial Superior Olive Neuron Models 10.3.2.1 Hodgkin-Huxley-Type Medial Superior Olive Models 10.3.2.2 Integrate-and-Fire-Type Medial Superior Olive Models 10.3.2.3 Medial Superior Olive Models Without Membrane Potential 10.3.3 Lateral Superior Olive Neuron Models 10.3.3.1 Hodgkin-Huxley-Type Lateral Superior Olive Models 10.3.3.2 Integrate-and-Fire-Type Lateral Superior Olive Models 10.3.3.3 Lateral Superior Olive Models Without Membrane Potential 10.3.4 Applications of Medial Superior Olive/Lateral Superior Olive Models 10.3.4.1 Model Comparison 10.3.4.2 Simulations with Arbitrary Sound Stimuli 10.3.4.3 Simulations of Hearing Impairment and Electrical Hearing 10.3.5 Models of the Inferior Colliculus 10.4 Simulating Psychoacoustic Data 10.4.1 Decoding the Output of Binaural Nuclei 10.4.2 Binaural Unmasking 10.4.3 Perceptual Discrimination 10.4.4 Laterality and Localization 10.5 Summary and Future Directions References Chapter 11: Clinical Ramifications of the Effects of Hearing Impairment and Aging on Spatial and Binaural Hearing 11.1 Introduction 11.2 Impairments of the Auditory System 11.2.1 Studying the Impacts of Impairments of the Auditory System on Binaural and Spatial Hearing 11.3 Evidence from Self-Report 11.4 Evidence from Physiology 11.5 Evidence from Behavioral Measures 11.5.1 Localization 11.5.2 Interaural Time Differences 11.5.3 Interaural Level Differences 11.5.4 Auditory Source Width Sensitivity 11.6 Spatial Release from Masking 11.7 Central Auditory Processing of Binaural and Spatial Cues 11.8 Modeling Binaural and Spatial Hearing in Older and Hearing-Impaired Listeners 11.9 Multifactorial Approaches 11.10 Current Evaluation Techniques 11.11 Clinical Ramifications 11.12 Conclusions and Future Directions References Chapter 12: Physiology of Higher Central Auditory Processing and Plasticity 12.1 Introduction 12.2 Auditory Cortex 12.2.1 Cortical Areas Necessary for Sound Localization 12.2.2 How Is Sound Location Represented by Neurons in Auditory Cortex? 12.2.2.1 Encoding Interaural Level Differences 12.2.2.2 Encoding Interaural Time Differences 12.2.3 Spatial Receptive Fields in Auditory Cortex 12.2.4 Spatial Receptive Fields During Behavior 12.2.5 How Is Spatial Information Extracted from Auditory Cortical Responses? 12.3 Spatial Processing in Brain Networks 12.3.1 The Dual-Stream Theory 12.3.2 Cortical Processing of Space Outside Auditory Cortex 12.3.2.1 Frontal Cortex 12.3.2.2 Parietal Cortex 12.3.3 Beyond “What Versus Where” 12.3.3.1 Using Binaural Cues in Auditory Scene Analysis 12.3.3.2 Perception-Action Pathway 12.3.3.3 Descending Connections 12.4 Plasticity: Adaptive Encoding of Auditory Space 12.5 Unanswered Questions 12.5.1 Does the Auditory Cortex Represent Space or Acoustic Localization Cues? 12.5.2 Representing Sound Location in Multiple Coordinate Frames 12.6 Chapter Summary References Chapter 13: Binaural Hearing with Devices 13.1 Hearing with Devices 13.1.1 Amplification of Sound with Hearing Aids 13.1.2 Recovery of Hearing with Cochlear Implants 13.2 Bilateral Hearing with Devices 13.2.1 Bilateral Benefits with Hearing Aids 13.2.2 Bilateral Benefits with Cochlear Implants 13.3 Factors Affecting Binaural Hearing with Devices 13.3.1 Sound Acquisition and Delivery 13.3.2 Signal Processing 13.3.2.1 Hearing Aids 13.3.2.2 Cochlear Implants 13.3.3 Beamforming Technology 13.3.4 Attempts to Limit Interaural Distortion 13.3.5 Patient Factors 13.3.6 Contralateral Interference for Speech 13.4 Summary References Correction to: Computational Models of Binaural Processing