The hearing sciences

Contents
Preface
Reviewers
About the Authors
Section I. Basic Acoustics and Instrumentation
	1 Physical Properties of Sound
		Energy
		Opposing Forces
		Units of Measurement
		Sound Energy
		Compression and Rarefaction
		Frequency
		Intensity
		Limits of Human Frequency Detection
		Summary
		Review Questions
	2 Ratios, Logarithms, and Decibels
		Why Do We Need the Decibel?
		Creating a More Workable numbering System for Measuring Sound and Hearing
			Base 10 Exponents
			Expressing Pressure Measurements with Base 10 Exponents and Significant Digits
			Adding and Subtracting Numbers in Scientific Notation
		Logarithms Are Based on Exponents
			Logarithms of Numbers With Only 1 and 0
			Logarithms of Numbers Other Than 1 and 0
			Why Are Logs and Antilogs Important?
			Antilogs
			The Log of X Times Y
			Log of (X Divided by Y )
			Hints on Using the Calculator
			Obtaining the Log of a Number That Is Raised to a Power
		The Decibel
			Power
				Doubling Power
			Pressure
				Doubling Power Does Not Double Pressure
				Doubling the Distance from the Source
			More Practice at Calculating Sound Pressure Levels
			More Practice at Calculating Intensity Levels
			Relative Powers and Pressures
		Adding Decibels
		Summary
		Review Questions
	3 Further Examination of Properties of Sound
		Speed of Sound Transmission
		Wavelength
		Period
		Relationship of Period and Wavelength
		Sound Transmission Effects
			Diffraction and Reflection
			Sound Absorption, Transmission Loss, and Reverberation Time
			The Doppler Effect
			Sonic Booms and Thunder
			Temperature Changes Affect Speed of Sound
			Wind Effects
		Types of Decibel Scales
			Review of dB SPL and dB IL
			dB Increase
			dB HL and dB SL
		Introduction to The Audiogram
		Summary
		Review Questions
	4 The Sine in Sine Waves, Other Types of Sound Waves, and Introduction to Filters and Frequency Analysis
		Triangles and Sines
		Plotting Sine Waves
		Simple Harmonic Motion, the Pendulum, and the Circle
		Molecular Vibration and The Sine Wave
		How We Calculate Sine Wave Relative Amplitude When Phase is Known (or Calculated)
		How We Calculate Sine Wave Phase When Time and Frequency Are Known
		Review Questions
		Velocity and Acceleration
			Phase Relationships of Particle Displacement, Velocity, and Acceleration
		Complex Sound
			Summing Pure Tones That Differ Only in Phase or Amplitude
			Summing Pure Tones That Differ in Frequency
			Harmonics and Distortion Products
				Harmonic Distortion
				Other Distortion Tones
			Air Molecule Vibration Patterns for Complex Sounds
			Fourier’s Theorem
			Common Types of Tones and Noise
				Square, Triangular, and Sawtooth Waves
				Amplitude and Frequency Modulating Pure Tones
				White and Pink Noise
			The Click (Transient) Signal
			Waveform Rise and Fall Envelopes
		Introduction to Filtering
		Summary
		References
		Additional Review Questions
	5 Impedance, Energy Transfer, and Resonance
		Impedance
			Mass and Stiffness Forces are 180 Degrees Out of Phase
			Formula for Impedance
			The Meaning of Impedance (Z)
			The Meaning of Phase Angle
			Impedance of a Medium
			Alternative Formula for Impedance
		Acoustic Admittance
		Energy Transfer
		Resonance of Systems
		Standing Waves and Resonance of Tubes
			Standing Waves
			Resonance of a Tube Closed at One End
				Why a Glass Beer Bottle Resonates When You Blow Across the Top, but a Plastic Soda Bottle Not So Much
			Resonance of a Tube Closed at Both Ends
		Summary
		References
		Review Questions
	6 Electricity and Analog Systems
		Electron Flow
		Ohm’s Law
		Electrical Circuits
		What is Alternating Current (AC) Electricity?
			How is AC Sound Created by an AC-Powered Amplifier Circuit? Is It Different Than in a DC-Powered Amplifier?
		Ion Flow
		Introduction to Common Analog Components
			Microphones
			Amplifiers
			Filters
				Calculating Filter Cutoff Frequencies
				Cutoff Frequencies Defined at 3-dB Down Points
			Speakers
			Transducers
			Volume Controls
			Frequency Response Controls
		Summary
		Review Questions
	7 Digital Systems and Digital Signal Processing
		Bits and Sampling Rates
			How Big Is That?
			How Often Should Amplitude Be Measured?
			Building an Analogy to Use Later
		Additional Digitization Concepts
			Analog to Digital Converters
			Nyquist Frequency
				Aliasing
				Anti-Aliasing Filtering
		Digital to Analog Converters
			Imaging
			Anti-Imaging Filters
		Overview of What a Digital System Can Do
		Fast Fourier Transform (FFT) Analysis of Auditory Signals
			Windowing
				Overlapping Windows
			Goal of FFT Analysis
				FFT Resolution
				Example FFT Results
				Digital Noise in the FFT Analysis
				Calculating Noise per Bin and Decibel of Bandwidth per Bin
		Time-Domain Signal Averaging
			Hearing Aid Digital Noise Reduction
		Summary
		Review Questions
	8 Equipment Used in Audiology and Hearing Science
		Audiometers
		Signal Generators
		Sound Booths
		Immittance Devices (Middle Ear Analyzers)
			Tympanometers
			Measurements of Middle Ear Absorption and Reflectance
			Acoustic Stapedial Reflex Measurement
		Otoacoustic Emission Devices
			Spontaneous Otoacoustic Emission Measurement
			Transient-Evoked Otoacoustic Emission Measurement
			Distortion-Product Otoacoustic Emission Measurement
			Signal Processing Used in Analysis of All Types of Otoacoustic Emission Measurements
		Auditory Evoked Response Measurement Systems
			Common Mode Rejection
			Time-Domain Signal Averaging and Artifact Rejection
			Filtering the Evoked Response
		Hearing Aid Analyzers
		Real-Ear Measurement Systems
			Speech Mapping Technology
			Original Real-Ear Testing
		Components: Detailed Information
			Review of Current: Alternating Current (AC) and Direct Current (DC)
			What Is a Conductor, an Insulator?
			Semiconductors
				“Doping” Silicon to Make it More or Less Likely to Take/Give Electrons
				“Doping” Silicon to Make it More or Less Likely to Take/Give Electrons
			Diodes
			Transistors
				How a Transistor Acts As an Amplifier
				How a Transistor Acts As a Switch
			Resistors and Resistance in Circuits; More on Ohm’s Law
				Resistor Appearance and Coding
				Ohm’s Law Review
				Resistors in Series
				Resistors in Parallel
			Batteries in Series and in Parallel
			Capacitors
				Review of Alternating Current (AC) and Direct Current (DC)
				Capacitors Block Direct Current, Pass Alternating Current
			Inductors
		Power Supplies for Hearing instruments and Testing Equipment: Safety Concerns and Electronic Noise
			Relative Safety of AC and DC Power Supplies
			Grounding Equipment, Fuses, and Circuit Protectors
			Regulated Power Supplies and Power Conditioners
			Surge Protectors/Spike Arrestors
			Arc Fault Circuit Interrupters
			Ground Noise
			Floor Noise
		Microphones
			Types of Microphones
			Microphone Directionality
			Microphone Care
		Sound Level Meters
			Calibration of Sound Level Meters
			Types of Decibel Scales
			Sound Level Meter Response Times
			Decibel Range Selection
			Earphone Couplers
			Calibration of Audiometer Output Level: Reference Equivalent Threshold Sound Pressure Levels
		Frequency Counters
		Audiometer Calibrators
		Oscilloscopes
		Summary
		Review Questions
Section II. Introduction To Speech Acoustics
	9 Classification of Speech Sounds
		Consonants, Vowels, and Dipthongs
		Consonants Are Categorized by Place of Articulation, Manner of Articulation, and Voicing
			Alveolar Sounds
			Palatal Sounds
			Glottal Sound
			Velar Sounds
			Linguadental Sounds
			Bilabial Sounds
			Labiodental Sounds
		Vowels Differ in Tongue Height, Placement, Tension, and Lip Rounding
			Front Vowels
			Central Vowels
			Back Vowels
		Summary
		Review Questions
	10 Acoustics of Speech
		How Speech Sound Waveforms Can Be Viewed
		Fundamental Frequency, Glottal Pulses, Harmonics, and Format Frequencies
		Acoustic Characteristics of Vowels
			Formant Frequencies Are Created by Resonance of the Vocal Tract
			F1 and F2 of Vowels
			Intensity of Vowel Sounds
			Low Importance of Vowels for Speech Understanding
		Acoustic Characteristics of Consonants
			Stop Consonants Contain Wideband Energy
			Voice Onset Time Distinguishes Voiced and Unvoiced Sounds
			Formant Frequency Transitions Provide Additional Acoustic Cues
			Fricatives Have Longer Duration and More High-Frequency Energy
			Affricatives Have Characteristics of Both Plosives and Fricatives
			Nasals Have Low-Frequency Energy (Nasal Murmur) and Antiresonances
			Glides Are Characterized by Vowel Formant Transitions
			Intensity of Consonants
			Importance of Consonants for Speech Understanding
		Summary
		Reference
		Review Questions
Section III. Anatomy and Physiology of the Ear
	11 Overview of Anatomy and Physiology of the Ear
		Anatomic Terms for Location
		Anatomic Views
		General Sections of the Ear
		The Temporal Bone
		Lobes of the Brain
		Overview of Physiology
		Summary
		References
		Review Questions
	12 Introduction to the Conductive Mechanisms
		The External Ear
		The Middle Ear
			The Tympanic Membrane
			The Middle Ear Space
			The Ossicles
			Overview of How Middle Ear Ossicular Motion Permits Hearing
			Middle Ear Muscles
			The Eustachian Tube
			Medial Wall
			Posterior Wall
			The Lateral or Tympanic Wall
			Anterior Wall
			Superior Wall
			Inferior Wall
		Summary
		Review Questions
	13 Introduction to the Physiology of the Outer and Middle Ear
		Resonances of the External Ear
		Energy Transfer Through the Middle Ear
			Impedance Mismatch between Air and Cochlear Fluids
			The Middle Ear as an Impedance-Matching Transformer
				Ossicular Lever
				Areal Ratio
		The Acoustic Reflex
		Summary
		References
		Review Questions
	14 Bone-Conduction Hearing
		Bone-Conduction Mechanisms
			Skull Vibration: Distortional Aspect of Bone-Conduction Hearing Introduced
			Inertial Aspects of Bone Conduction
			Further Discussion of the Distortional Aspects of Bone Conduction
			Osseotympanic Aspects of Bone Conduction: Bone Conduction by Air Conduction
		Hearing is Tested by Air and Bone Conduction
			Bone Conduction by Air Conduction (Osseotympanic Bone Conduction) and the Occlusion Effect
		Summary
		References
		Review Questions
	15 Advanced Conductive Anatomy and Physiology
		Pinna
			Embryologic Development
			Landmarks
			Physiology of the Pinna
		External Auditory Meatus
			Detailed Anatomy
			Proximity of the Temporomandibular Joint
			Proximity of Nerves to the External Auditory Meatus
			Skin of the External Auditory Meatus
			Cerumen
			Detailed Physiology of the External Auditory Meatus
		Tympanic Membrane
			Slant and Cone Depth
			Third Impedance Matching Transformer Mechanism
		Detailed Study of the Ossicular Chain
		Resonance of the Middle Ear
			Mass and Stiffness of the Middle Ear Affect Sound Transmission Differently at Different Frequencies
			Pathology Changes Middle Ear Sound Transmission
		Acoustic Reflex Physiology
			Reflex Latency
			Reflex Adaptation
			Reflex Threshold
		Summary
		References
		Review Questions
	16 Introduction to the Sensory Mechanics
		The Bony Labyrinth
		The Membranous Labyrinth
			The Vestibular System
			The Cochlea
		Structures Within the Cochlea
			Gross Structures
			Fine Details of Features in the Cochlea
			Mass and Stiffness Differences along the Basilar Membrane
			Review of How the Detailed Features Fit Within the Larger Picture
		Cochlear Blood Supply
		Innervation of the Cochlea
		Summary
		References
		Review Questions
	17 Advanced Study of the Anatomy of the Cochlea
		Hair Cell Height and Number
		Stereocilia and Their Tip Links and Side Links
		Supporting Cells
		Chemical Composition of Endolymph and Perilymph
		Comparative Electrical Charges of Fluids in the Cochlea
		Potassium Influx Regulates Calcium Coming Into Hair Cells
		Ion Changes in the Hair Cell and Circulation of Ions
		Neurotransmitter Release
		Summary
		Review Questions
	18 Introduction to Cochlear Physiology
		Arrangement of the Cilia Relative to the Tectorial Membrane
		Mass/Stiffness Gradient of the Basilar Membrane
		Review of Divisions and Membranes Within the Cochlea
		The In-and-Out Motion of the Stapes Footplate Becomes an up-and-Down Motion of the Basilar Membrane, Called the Traveling Wave
		The Location of the Maximum Place of Movement on the Basilar Membrane is Determined by the Sound Frequency
		An Unfortunate Untwisting of Fate
		The Height of the Traveling Wave Envelope is Related to Sound Intensity
		Ciliary Shearing
			Returning to the Concept That the Up-and-Down Basilar Membrane Motion Creates Side-to-Side Shearing of the Hair Cell Cilia
			Shearing of Cilia Opens Microchannels (Mechanoelectrical Transduction Channels) in the Cilia and Creates Chemical Changes in the Hair Cell Body
		The Outer Hair Cell Active Mechanism Enhances the Motion of the Inner Hair Cell Cila
		Hearing Requires Inner Hair Cell Stimulation
		Summary
		Reference
		Review Questions
	19 More Hair Cell Physiology
		Calcium and Potassium Channels, Prestin, and Active Cilia
			Review of Cellular Chemistry Changes
			Prestin Protein Contraction Creates the Active Mechanism
			Hair Cell Cilia Also Appear to Have Active Properties
			Tip Links and MET Channels in Outer and Inner Hair Cell Stereocilia
		Otoacoustic Emissions are Sounds that Come From the Cochlea as a Result of the Active Mechanism(s) of the Outer Hair Cells
			Are Cilia Responsible for Otoacoustic Emissions?
			What Are the Places on Basilar Membrane for Creation of the Otoacoustic Emission?
		Prestin Kockout Mice
		Tip Links and Insertion Plaques: Slow Cilia Adaptation
		Apoptosis: A Bettwe Way for Hair Cells to Die
			Reactive Oxygen Species
			Antioxidants
			Melanin to the Rescue
		How the Traveling Wave is Altered by the Active Mechanism of the Cochlea
		Two-Tone Supperssion is Related to the Active Mechanism
		Summary
		Reference
		Review Questions
	20 Overview of Cochlear Potentials and the Auditory Nervous System
		Chemical Changes in the Hair Cells and Neurons
			The Cochlear Microphonic
			The Summating Potential
			Action Potentials
		Pattern of Neural Firing Encodes Frequency and Intensity
		The Primary Afferent Auditory Pathway
			Location of Afferent Neuron Dendrites
			Course of the VIIIth Nerve
			Cerebellopontine Angle
			Nuclei
			Primary Auditory Cortex
		Introduction to Efferent Neurons
		Summary
		References
		Review Questions
	21 Advanced Study of Cochlear and VIIIth Nerve Potentials
		Characteristic Frequency
		Cochlear Resting Potentials
			Endocochlear Potential
			Intracellular Potentials
		Cochlear Receptor Potentials
			Cochlear Microphonic
			Summating Potential
			Comparison of the Tuning of the Cochlear Microphonic and the Summating Potential
			Summary of Cochlear Microphonic and Summating Potential
		Action Potentials
			Electrical Potentials in Neurons
			N1 and N2 Responses of the VIIIth Nerve
			Refractory Period
			Spontaneous Discharge Rates
			Threshold of Neural Firing Is Related to Spontaneous Discharge Rate
			Firing Rates Are Influenced by Efferent Innervation
			Pure-Tone Frequencies and Intensities That Cause a Neuron to Fire Faster Than Spontaneous Rate
			Upward Spread of Masking: Masking of One Stimulus by a Second Stimulus
		Neural Tuning Curves
			How Tuning Curves Are Obtained
			Q10 dB Calculations Describe Width of Tuning Curve Tips
		Summary
		References
		Review Questions
	22 How Frequency and Intensity Information Are Encoded
		The Neural Action Potential
			Cell Membrane Characteristics
			How the Action Potential Is Initiated
			Propagation of the Action Potential Down the Axon
		Rate of Firing of One Neuron Increases as the Stimulus Frequency Approaches the Characteristic Frequency
		Different Combinations of Frequency and Intensity Can Create the Same Overall Number of Neural Discharges Per Second
		Problems with the Theory that Frequency is Encoded by Rate of Discharge
		Pattern of Neural Discharge Encodes Frequency and Intensity
			Additional Information Is Obtained From Early and Late Neural Firings
		Period Interval Histograms: Histograms Obtained with Pure-Tone Stimulation
		Review of the Response of the VIIIth Nerve to Pure Tones
		Limits of a Neuron’s Phase-Locking Ability
		Peristimulus Time Histograms for Longer Duration Tone Segment
		Whole Nerve Potentials Reveal Signal Intensity
		Masking of One Sound by a Second Sound
		Two-Tone Supperssion
		Response of the VIIIth Nerve to Complex Signals
		Poststimulus Time Histograms Obtained When Stimulating the Ear with Clicks and the Concept of Preferred Intervals
			Response of Multiple Neurons of the Same Characteristic Frequency
		Neural Encoding at Cochlear Nucleus and Higher Central Auditory Nuclei
			Neural Cell Types (Appearance) in the Central Nervous System
			Multiple Inputs to a Higher-Order Neuron Allows Alteration of Its Response Characteristics
				Coincidence Detectors Improve Phase-Locking
				Neurons May Be Excited by Differing Frequency Inputs
			Peristimulus Time Histograms of Higher-Order Neurons
			What Does the Variability in Cell Morphology, Tuning, and Neural Discharge Patterning Mean About Speech Encoding?
		Encoding of Information Necessary for Sound Localization and Lateralization
			Superior Olivary Complex Neurons Respond to Binaural Differences
			Superior Olivary Complex Allows for Sound Fusion
			Nuclei Are Tonotopically Organized
			Nuclei Superior to Superior Olive
		The Auditory Cortex
		Summary
		References
		Review Questions
	23 The Efferent Auditory System
		Olivocochlear Bundle
			Medial Efferent System
			Lateral Efferent Systems
			Crossed and Uncrossed Efferent Fibers
			Effect of Activation of the Efferent System
				Medial Efferent System Activation
				Lateral Efferent System Activation
			Memory Aids
		Other Efferent Pathways
		The Acoustic Reflex
			Stapedial Reflex Pathway
			Effect of Stapedial Reflex Contraction
			Role of Tensor Tympani
			Acoustic Reflexes Elicited by Nonauditory Stimuli
		Summary
		Review Questions
	24 Introduction to Peripheral Vestibular Anatomy and Physiology
		The Vestibular System: Bony and Membranous Labyrinths
			Arrangement of the Semicircular Canals
			Planes of the Canals of the Right and Left Ears Are Aligned
		Anatomy and Physiology of the Semicircular Canals
			Structures within the Ampullae of the Semicircular Canals
			Angular Head Motion Directions
			Cilia and Kinocilium in the Ampullae
			Direction of the Endolymph/Cupula Movement That Is Excitatory
		The Utricle and The Saccule
			Hair Cells of the Utricle and Saccule
		Vestibular Branch of the VIIIth Nerve
		Summary
		Reference
		Further Reading
		Review Questions
	25 Introduction to Central Vestibular Anatomy and Physiology
		Functions of the Balance System
			Awareness of Head Position
			The Vestibulo-Ocular Reflex
				Ewald’s First Law
				Muscles Controlling Eye Movements
				Cranial Nerves of the Extraocular Muscles
				Pathways From the Vestibular Nucleus to the Nerves Controlling Eye Movement
				Neural Control of Eye Deflection During Head Turn
				Limited Range of Eye Deflection
				Nystagmus: Repeated Slow Drift, Rapid Saccadic Return Motion
				Introduction to Ewald’s Second Law
				Summary of the Vestibulo-Ocular Reflex and Introduction to Videonystagmography Testing
				Velocity Storage
			Reflexes of the Balance System for Postural Control
				Vestibulospinal Reflex
				Cervico-Ocular Reflex
				Cervicospinal and Cervicocollic Reflexes
				Vestibulocervical and Vestibulocollic Reflexes
			Summary of the Functions of Balance and Clinical Implications
		Summary
		Review Questions
	26 Advanced Vestibular Anatomy and Physiology
		Size of the Vestibular System
		Endovestibular Potentials
		Frequency in the Vestibular System
			The Vestibulo-Ocular Reflex in Response to Head or Body Rotation: Superimposed Nystagmus Beats
			Frequency in Caloric Testing
		Morphology of the Hair Cells of the Crista Ampullaris
			Is There an Active Mechanism in the Vestibular System?
		Characteristics of the First-Order Vestibular Neurons
			Calyx, Bouton, and Dimorphic Neurons
			Characterization of Neurons by Diameter
			Neural Firing Rates and Patterns
			Peripheral Areas of the Ampulla Encode Low-Frequency Stimulation
			Afferent Neurotransmitters
			Bidirectional Change in Firing Rate of Afferent Neurons
		Efferent Innervation of the Crista Ampullaris
		Detailed Study of Eye Muscle Attachments
			Review of the Eye Muscles
			Eye Movement from Superior/Inferior Obliques and Superior/Inferior Recti: Not Exactly As Expected From the Diagrams
		Influence of the Canals
			Tonic Contraction in the Absence of Movement, Head Movement Alters Contraction Strength
			Analogy of a Catamaran
			Horizontal Canal Control of Eye Movement
			Vertical Semicircular Canal Mediated Control of Eye Movement
				Left Posterior Canal
				Right Posterior Canal
				Left Anterior Canal
				Right Anterior Canal
		Semicircular Canal Neural Connections
			Review of Gross Vestibular Neural Anatomy
			Excitatory and Inhibitory Responses in the Second-Order Vestibular Neurons
			Connection to the Cranial Nerves That Control Eye Movement
		Macula and Its Vor Pathways
			Review of the Structure and Function of the Macula of the Utricle and Saccule
			The Otoconia Cause the Macula to Sense Gravity and Respond to Head Tilt
			Connections Between Utricle and Extraocular Muscles
			Connections Between the Saccule and Extraocular Muscles
			Type I and Type II Hair Cells of the Macula
		Neural Plasticity in the Central Vestibular System
		Summary
		References
		Review Questions
Section IV. Basic Psychoacoustics
	27 Introduction to Psychoacoustics
		Threshold (In Decibel Sound Pressure Level) for Pure Tones Depends on Frequency
		Two Ears are Better Than One
		Under Ideal Circumstances, A Person Can Detect a 1-dB Intensity Change
		In General, a 10-dB Increase in Intensity is About a Doubling of Loudness (Some Studies Say 6 dB)
		Loudness Grows a Bit Differently in the Low Frequencies: An Introduction to Phon Curves
		Pitch
			When Is a Pure Tone Tonal?
			Detecting Change in Pitch
			Doubling Frequency Creates a Musical Sameness But Not a Doubling of Pitch
		Masking
			Upward Spread of Masking
			Critical Bands
		Temporal Processing
			Sounds Are Louder and More Tonal if at Least One-Quarter-Second in Duration
			Temporal Order Detection
			Gap Detection
		Summary and Implications for Speech Perception
		Review Questions
	28 Classical Psychoacoustical Methodologies
		Classical Psychoacoustical Methods
			Method of Limits
				Effect of Instruction, Motivation, and Willingness to Guess
				Response Latency and False Positive Responses
				Effect of Using Increasing Versus Decreasing Intensity Runs
			Method of Adjustment
				Similarity of Results of Method of Adjustment and Method of Limits
			Method of Constant Stimuli
				Number of Trials and Step Size
		Introduction to Forced-Choice Methods
			Threshold Is Not 50% Correct Identification in a n-Interval Forced-Choice Procedure
		Introduction to Signal Detection Theory
		Adaptive Procedures
		Scaling Procedures
			Magnitude Estimation
			Magnitude Production
			Fractionation
			Cross-Modality Matching
		Summary
		Reference
		Review Questions
	29 Signal Detection Theory and Advanced Adaptive Approaches
		Signal Detection Theory
			Understanding “Magnitude of the Sensory Event”
			Signal-Plus-Noise Perception
			Criterion Points for Decision Making, and How Hit and Correct-Rejection Percentages Reveal Spacing Between the Noise and Signal-Plus-Noise Distributions
			Altering Subject Criteria in Signal Detection Theory and Receiver Operating Curves
			The Magic of d′
		Adaptive Methods to Determine the Signal Level That is Correctly Detected a Given Percentage of the Time
			Change the Rules for When to Increase/Decrease Magnitude in Order to Estimate Different Percent Correct Points
			Example of Rules Used to Find Threshold in a Three-Alternative Forced-Choice Experiment
			Adaptive Procedures Can Be Used to Obtain the Response Function Curve
			Disadvantage to a Block Up–Down Procedure
			Interleaving Runs
			Parameter Estimation by Sequential Testing
		Gridgeman’s Paradox
		Preference Testing in Hearing Aid Customization
			Paired Comparisons
		Summary
		Reference
		Further Reading
		Review Questions
	30 Threshold of Hearing, Loudness Perception, Just Noticeable Difference for Loudness, and Loudness Adaptation
		Absolute Threshold of Hearing
			Minimal Audible Pressure and Minimal Audible Field
			Binaural and Equated Binaural Thresholds
			Effect of Stimulus Duration on Absolute Threshold
			Effect of Stimulus Repetition Rate
		Difference Threshold For Intensity (DLI)
			Spectral Profile Analysis
		Loudness Perception
			Loudness Level
			Decibel Scales Revisited
			Loudness Scaling
		Loudness Adaptation
		Temporary Threshold Shift
		Summary
		References
		Review Questions
	31 Calculating Loudness
		Physiologic Correlates of Loudness and Loudness Growth
			The Transfer Function of the Ear
			Active Mechanism Less Effective at Low Frequencies
			Role of the Active Mechanism for Varying Intensity Level Sounds
			Spread of Activity Along the Basilar Membrane
		Calculating Loudness of Pure Tones
		Complex Tone Loudness
		Summary
		References
		Review Questions
	32 Basics of Pitch Perception
		Pitch Perception
			Limits of Tonal Perception
			Pitch Perception Is Intensity Dependent
			Pitch Perception Is Duration Dependent
		Pitch Scaling
			The Mel Scale of Pitch (and Other Pitch Scales)
			Octave Scales
			Bark Scale
		Just Noticeable Difference of Frequency
			Changes in DLF with Frequency
			Changes in DLF with Intensity
			Make Sure You Are Measuring a DLF and Not a DLI!
		Perception of Two Tones and of Distortions
			Beats and Simple Difference Tones
			Aural Harmonics, Summation Tones, and Other Difference Tones
		Summary
		References
		Review Questions
	33 Introduction to Masking
		Tone-on-Tone Masking
		Critical Bands
		Summary
		Reference
		Review Questions
	34 More About Masking and Cochlear Frequency Distribution
		Masking Pure Tones with White Noise and Narrowband Noise: Critical Bands and Critical Ratios
			Level per Cycle Calculations
			Critical Bands in Hz and in Decibels
			A Critical Band Is Also Called a Bark
			How Critical Bands Vary With Frequency
			Fletcher’s Theory of Critical Ratio
		Equivalent Rectangular Bandwidths
		Other Ways to Evaluate Critical Bands
		Cochlear Maps From Critical Bands
		The Relationship Between DLF, Critical Ratios, and Equivalent Rectangular Bandwidths
		Comodulation Release From Masking
		Remote Masking
		Summary and Some Further Analysis
		References
		Review Questions
	35 Psychophysical Tuning Curves
		Psychophysical Tuning Curves (PTCS)
			How PTCs Are Obtained and Interpreted
			Correlation to Traveling Wave Locations
			Families of PTCs
			Tips, Tails, and Q10 dBs
		Neural Tuning Curves Revisited
		The Link Between PTCs and Neural Tuning Curves
		Summary and a Confession
		Review Questions
	36 Temporal Processing
		Review of Temporal Integration for Threshold-Level Stimuli
		Review of Duration Effects on Pitch Perception
		Gap Detection
			Gap Detection Ability Is a Function of Frequency
			Gap Detection Ability Is Related to the Auditory Filter Bandwidth
			Detection of Gaps in White Noise Uses the High-Frequency Cochlear Filters
		Temporal Successiveness
		Temporal Discrimination
			Temporal Discrimination Relates to Distinguishing Voiced From Unvoiced Consonants
			Temporal Modulation Transfer Functions
		Summary
		References
		Review Questions
	37 Temporal Masking
		Forward Masking: Masker Comes Before Probe Signal
			Magnitude of the Effect
			Physiologic Explanations
			Forward Masking Psychophysical Tuning Curves Are Sharper
		Backward Masking: Masker Follows Probe Signal
			Magnitude of the Effect
			Physiologic Explanation
		Summary
		Reference
		Further Reading
		Review Questions
	38 Binaural Hearing
		Binaural Summation
		Improved DLI and DLF Ability Binaurally
		Binaural Beats
		Central Masking
		Binaural Fusion
		Localization
			Temporal Cues to Localization
			Intensity Differences
			Combined Effect of Intensity and Phase Differences
			Central Nervous System Cells Are Responsive to Phase or Intensity Differences
		Lateralization
			Interaural Time Difference
			Interaural Intensity Differences
			Combined Effects of Intensity and Phase
			Why Is Lateralization a Different Phenomenon From Localization?
		Masking Level Differences
		Summary
		References
		Review Questions
	39 Introduction to the Results of Psychoacoustical Assessment of Persons With Hearing Impairment
		Effect of Hearing Loss on Audibility of Tones and Speech
			Effect of Loss Type and Severity
			Loss of Sensitivity for Pure Tones Predicts Loss of Speech Perception Ability
			Articulation Index Predictions of Speech Understanding Are Imperfect
		Cochlear Loss Causes Recruitment
		Difference Limens for Intensity
		Threshold Temporal Summation Effects
		Widened Psychophysical Tuning Curves
		Cochlear Dead Regions
			Off-Frequency Listening
			Audiometric Characteristics of Dead Regions
			What Is Perceived When Off-Frequency Listening Occurs?
			Psychophysical Tuning Curves for Dead Regions
			Threshold Equalizing Noise (TEN) Test
			Enhanced DLFs Near Dead Regions?
			Amplification for Those With Dead Regions
		Gap Detection Thresholds
			Results With White Noise Stimuli
			Gap Detection Results for Pure Tones Depend on Stimulus Intensity Levels
			Gap Detection Levels ShouldT heoretically Be Better in Hearing-Impaired Persons
		Temporal Modulation Detection Ability is Good if the Signal is Full Audible
		Ability to Detect Very Fast Signal Changes in Frequency and Amplitude is Poorer Than for Normal Hearers
		Poorer Pitch Perception Abilities
		Failure to Take Advantage in Pauses in Interrupted Noise
		Summary
		References
		Further Reading
		Review Questions
Appendix A. The Math Needed to Succeed in Hearing Science
Appendix B. Answers to Review Questions
Index