Psychoacoustics

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Psychoacoustics

• Psychophysics
• Study of the relationship of the psychological
  and physical aspects of a stimulus.
• Psychoacoustics
• The psychophysics of the auditory system

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Measurement Methods

• Background
• Absolute threshold or absolute limen
• Smallest stimuli that a person can detect.
• Difference threshold or difference limen
• Smallest difference that a person can detect
  between two stimuli

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Classical Measurement Methods

• Method of limits
• Method of adjustment
• Method of constant stimuli

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Method of Limits
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Method of Limits for Clinical Audiometry
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Method of Limits for Difference Limen
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Method of Adjustment

• Subject controls stimulus

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Method of Constant Stimuli
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Signal Detection Theory

• Threshold Measurement
• Test Evaluation

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How does SDT control for listener bias?

• Aggressive listener will have a yes bias
• High hit rate but also a high false alarm rate
• Passive listener will have a no bias
• Low hit rate but will have a low false alarm rate.

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Receiver Operator Characteristic (ROC) curve
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Other Measurement Methods

• Magnitude Estimation
• Subject estimates magnitude of the stimulus
• Ratio Comparison
• Subject perceives a ratio between two stimuli
• Cross-modality matching
• Matches magnitude between two stimuli. e.g.,
  visual, auditory, somatosensory, olfactory, or
  shock.

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Summary