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| Preface | |
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| Physiological Aspects of Cochlear Hearing Loss | |
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| Introduction | |
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| Linear and Nonlinear Systems | |
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| Structure and Function of the Outer and Middle Ear | |
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| Structure and Function of the Normal Cochlea | |
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| The cochlea, the basilar membrane and the organ of Corti | |
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| Tuning on the basilar membrane | |
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| The nonlinearity of input-output functions on the basilar membrane | |
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| Two-tone suppression | |
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| Combination tone generation | |
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| Responses of the basilar membrane to complex sounds | |
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| Otoacoustic emissions | |
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| Neural Responses in the Normal Auditory Nerve | |
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| Spontaneous firing rates and thresholds | |
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| Tuning curves and iso-rate contours | |
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| Rate-versus-level functions | |
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| Two-tone suppression | |
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| Phase locking | |
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| Types of Hearing Loss | |
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| Physiology of the Damaged Cochlea | |
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| Basilar membrane responses | |
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| Neural responses | |
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| Structure-function correlation | |
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| Otoacoustic emissions | |
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| Phase locking | |
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| Conclusions | |
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| Absolute Thresholds | |
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| Introduction | |
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| Measures of Absolute Threshold | |
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| Minimum audible pressure (MAP) | |
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| Minimum audible field (MAF) | |
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| Comparison of MAP and MAF | |
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| The audiogram | |
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| Descriptions of the Severity of Hearing Loss | |
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| Causes of Hearing Loss Due to Cochlear Damage | |
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| Perceptual Consequences of Elevated Absolute Thresholds | |
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| Masking, Frequency Selectivity and Basilar Membrane Nonlinearity | |
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| Introduction | |
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| The Measurement of Frequency Selectivity Using Masking | |
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| Introduction | |
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| The power-spectrum model | |
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| Estimating the shape of a filter | |
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| Estimating Frequency Selectivity from Masking Experiments | |
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| Psychophysical tuning curves | |
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| The notched-noise method | |
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| Characteristics of the Auditory Filter in Normal Hearing | |
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| Variation with centre frequency | |
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| Variation with level | |
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| Summary | |
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| Masking Patterns and Excitation Patterns | |
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| Masking patterns | |
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| Relationship of the auditory filter to the excitation pattern | |
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| Changes in excitation patterns with level | |
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| Possible effects of suppression | |
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| Non-Simultaneous Masking | |
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| Basic properties of non-simultaneous masking | |
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| Evidence for suppression from non-simultaneous masking | |
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| The enhancement of frequency selectivity revealed in non-simultaneous masking | |
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| Relation between the growth of forward masking and the basilar membrane input-output function | |
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| The Audibility of Partials in Complex Tones | |
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| Effects of Cochlear Damage on Frequency Selectivity in Simultaneous Masking | |
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| Complicating factors | |
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| Psychophysical tuning curves | |
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| Auditory filter shapes measured with notched noise | |
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| The Use of Masking to Diagnose Dead Regions | |
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| The threshold-equalizing noise (TEN) test | |
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| The TEN(HL) test | |
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| Prevalence of dead regions assessed using the TEN(HL) test | |
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| Effects of Cochlear Damage on Forward Masking and Suppression | |
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| Effects of Cochlear Hearing Loss on BM Input-output Functions 88 XII Perceptual Consequences of Reduced Frequency Selectivity, Dead Regions, Loss of Suppression and Steeper BM Input-output Functions | |
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| Susceptibility to masking | |
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| Timbre perception | |
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| Perceptual consequences of dead regions | |
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| Loudness Perception and Intensity Resolution | |
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| Introduction | |
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| Loudness Perception for Normally Hearing People | |
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| Equal-loudness contours and loudness level | |
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| The scaling of loudness | |
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| The detection of intensity changes | |
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| Effects of Cochlear Hearing Loss on Loudness Perception | |
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| A Model of Normal Loudness Perception | |
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| A Model of Loudness Perception Applied to Cochlear Hearing Loss | |
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| Introduction | |
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| Elevation of absolute threshold | |
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| Reduced compressive nonlinearity | |
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| Reduced inner hair cell/neural function | |
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| Reduced frequency selectivity | |
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| Complete loss of functioning IHCs or neurones (dead regions) | |
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| Using the model to account for loudness recruitment | |
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| Effects of Bandwidth on Loudness | |
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| Normal hearing | |
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| Impaired hearing | |
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| Effects of Cochlear Hearing Loss on Intensity Resolution | |
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| Perceptual Consequences of Altered Loudness Perception | |
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| Consequences of loudness recruitment and reduced dynamic range | |
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| Perceptual consequences of reduced loudness summation | |
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| Perceptual consequences of altered intensity discrimination | |
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| Temporal Resolution and Temporal Integration | |
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| Introduction | |
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| Modelling Within-Channel Temporal Resolution in Normal Hearing | |
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| Bandpass filtering | |
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| The nonlinearity | |
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| The sliding temporal integrator | |
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| The decision device | |
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| Characterizing the nonlinear device and the sliding temporal integrator | |
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| Temporal Resolution in Normal Hearing | |
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| The effect of centre frequency on gap detection | |
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| Temporal modulation transfer functions | |
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| The rate of recovery from forward masking | |
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| Temporal Resolution in People with Cochlear Damage | |
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| The influence of sound level on gap detection and the rate of decay of forward masking | |
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| The influence of audible bandwidth on temporal modulation transfer functions and gap detection | |
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| The influence of changes in the compressive nonlinearity | |
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| Temporal Integration at Threshold | |
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| Temporal integration in normally hearing people | |
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| Temporal integration in people with cochlear hearing loss | |
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| Explanations for reduced temporal integration in people with cochlear hearing loss | |
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| Temporal Integration at Suprathreshold Levels | |
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| Perceptual Consequences of Abnormal Temporal Processing in People with Cochlear Hearing Loss | |
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| Consequences of abnormal temporal resolution | |
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| Consequences of reduced temporal integration | |
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| Pitch Perception and Frequency Discrimination | |
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| Introduction | |
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| Theories of Pitch Perception | |
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| The Perception of the Pitch of Pure Tones by Normally Hearing People | |
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| The frequency discrimination of pure tones | |
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| The perception of musical intervals | |
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| The effect of level on pitch | |
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| Frequency Discrimination of Pure Tones by People with Cochlear Hearing Loss | |
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| Difference limens for frequency (DLFs) | |
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| Frequency modulation detection limens (FMDLs) | |
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| The Perception of Pure-Tone Pitch for Frequencies Falling in a Dead Region | |
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| Pitch Anomalies in the Perception of Pure Tones | |
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| The Pitch Perception of Complex Tones by Normally Hearing People | |
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| The phenomenon of the missing fundamental | |
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| Discrimination of the repetition rate of complex tones | |
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| Theories of Pitch Perception for Complex Tones | |
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| The representation of a complex tone in the peripheral auditory system | |
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| Spectro-temporal pitch theories | |
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| The relative importance of envelope and temporal fine structure | |
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| Pitch Perception of Complex Tones by People with Cochlear Hearing Loss | |
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| Theoretical considerations | |
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| Experimental studies | |
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| Perceptual Consequences of Altered Frequency Discrimination and Pitch Perception | |
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| Effects on speech perception | |
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| Effects on music perception | |
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| Spatial Hearing and Advantages of Binaural Hearing | |
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| Introduction | |
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| The Localization of Sinusoids | |
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| Cues for localization | |
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| Performance of normally hearing people in localization and lateralization | |
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| Performance of hearing-impaired people in localization and lateralization | |
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| The Localization of Complex Sounds | |
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| The role of transients and across-frequency comparisons | |
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| Performance of normally hearing people | |
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| Performance of people with cochlear hearing loss | |
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| Reasons for large interaural time difference and interaural level difference thresholds in people with cochlear hearing loss | |
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| The Cone of Confusion, Head Movements and Pinna Cues | |
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| The cone of confusion | |
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| The role of head movements | |
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| Information provided by the pinnae | |
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| Localization using pinna cues by normally hearing and hearing-impaired people | |
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| General Conclusions on Sound Localization | |
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| The Precedence Effect | |
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| The precedence effect for normal hearing | |
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| The precedence effect for impaired hearing | |
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| Binaural Masking Level Differences (MLDs) | |
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| MLDs for normally hearing people | |
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| Mechanisms underlying MLDs | |
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| MLDs for people with cochlear hearing loss | |
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| Possible reasons for smaller MLDs in people with cochlear damage | |
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| Head-Shadow Effects | |
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| Benefits of head shadow for normally hearing people | |
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| Benefits of head shadow for hearing-impaired people | |
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| Release from Informational Masking | |
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| Diotic Advantages | |
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| Perceptual Consequences of Abnormal Binaural and Spatial Hearing in People with Cochlear Damage | |
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| Speech Perception | |
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| Introduction | |
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| The Magnitude of the Noise Problem | |
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| The Role of Audibility | |
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| The Articulation Index (AI) and Speech Intelligibility Index (SII) | |
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| Use of the AI or SII to predict speech intelligibility for the hearing impaired | |
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| The intelligibility of speech in noise at high overall levels | |
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| Comparison of detection and recognition for speech in noise | |
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| The intelligibility of speech in quiet at high overall levels | |
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| Simulation of hearing loss by selective filtering (frequency-dependent attenuation) | |
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| Simulation of hearing loss by masking | |
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| Conclusions on the role of audibility | |
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| Influence of Dead Regions on Speech Perception | |
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| Correlation Between Psychoacoustic Abilities and Speech Perception | |
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| Assessing the Effects of Frequency Selectivity on Vowel and Consonant Perception | |
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| Consonant perception | |
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| Vowel perception | |
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| Influence of Loss of Sensitivity to Temporal Fine Structure | |
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| The Use of Simulations to Assess the Importance of Psychoacoustic Factors in Speech Perception | |
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| Simulations of loudness recruitment combined with threshold elevation | |
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| Simulations of reduced frequency selectivity | |
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| Simulation of the combined effects of threshold elevation, recruitment and reduced frequency selectivity | |
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| Simulation of reduced temporal resolution | |
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| Conclusions | |
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| Hearing Aids | |
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| Introduction | |
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| Linear Amplification | |
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| The difficulty of restoring audibility using linear aids | |
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| Prescriptive fitting rules for linear hearing aids | |
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| Compression Amplification | |
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| Basic characteristics of automatic gain control systems | |
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| Varieties of automatic gain control systems | |
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| Rationales for the use of multi-band compression (and noise reduction) | |
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| Research on the effectiveness of multi-band syllabic compression | |
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| Methods for initial fitting of hearing aids with multi-band compression | |
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| Methods for fine tuning hearing aids with multi-band compression | |
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| Slow-acting automatic gain control systems | |
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| Comparisons of slow-acting and fast-acting systems | |
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| General conclusions about compression | |
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| Some General Problems with Hearing Aids | |
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| Inadequate gain at high frequencies | |
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| Acoustic feedback | |
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| Peakiness of frequency response | |
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| The occlusion effect | |
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| Time delays | |
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| Methods for Improving the Speech-to-Noise Ratio | |
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| Multi-channel noise reduction | |
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| Directional microphones | |
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| Binaural processing algorithms | |
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| Transposition Aids for Severe and Profound Hearing Loss | |
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| Cochlear Implants | |
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| Concluding Remarks | |
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| Glossary | |
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| References | |
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| Index | |