PSYCO367 Chapter Notes - Chapter 11: Wave, Acoustic Reflex, Sound Intensity

• School: University of Alberta
• Department: Psychology
• Course: PSYCO367
• Professor: Shannon Wowk

Document Summary

Bird chirp sound stimulus (pressure changes in the air) representation of bird song in ear. Two definitions of sound": physical: sound is pressure changes in the air or other medium. Sound stimulus: perceptual: sound is the experience we have when we hear. Movements or vibrations of an object cause pressure changes. Air does not move out" from source, stays where it is but moves up and down: ex. dropping stone in water, water stays where it is, waves move up and down. Pure tones: changes in air pressure in sine wave pattern. Amplitude: the size of pressure changes: fluctuates from whisper to gunshot. Method: using decibels to shrink large ranges of pressures. The decibel scale related the amplitude of the stimulus with the psychological experience of loudness: db = 20 x logarithm (p/po) P = sound pressure we are considering. Po = reference pressure (typically 20 micropascals: ex.