PSYC 212 Chapter Notes -Basilar Membrane, Cochlea, Psychophysics
27 Oct 2012
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Document Summary
Hearing: perceptual experience of sound in the brain. Intensity perception is influence by frequency: audibility thresholds. Loudspeaker in a room, free-field, natural: minimum audible pressure (map) Maf appears to give lower threshold due to pinna amplification. Minimum threshold chosen at 50% detection level. Hearing sensitivity increases in 2000 - 4000 hz range (mid frequencies) Minimal audibility curve is a function of threshold sound detection and frequency. Hard to find absolute lowest frequency heard because it becomes a physical sensation. Maf lower than map by 6 db (outer ear augmentation) Duration of sound - over 200ms, integration occurs, hearing is maximized. Under 200ms, integration (temporal summation) doesn"t occur, hearing not maximized. Binaural summation - hearing is the sum of pressures over the whole system. Monaural is ~6 db higher (less sensitive) Dynamic range = suprathreshold until terminal threshold for frequencies 135 - 4000 hz: difference thresholds. Weber constant for intensity discrimination ~ 0. 1 - 0. 4.
