PSY 3108 Lecture Notes - Lecture 5: Sound, Density Of Air, Rarefaction

• School: University of Ottawa
• Department: Psychology
• Course: PSY 3108
• Professor: Charles Collin

Document Summary

Physical- sound is pressure changes in the air or other medium. Perceptual- sound is the experience we have when we hear. Sound waves- objects make sound by moving back and forth rapidly (20 to 20000 times/ sec) through a medium. Example- diaphragm moves out, pushing air molecules together (compression), and moves in pulling them apart (rarefaction) The cycle of this process creates alternating high and low-pressure regions that travel through the air. Sound waves are longitudinal waves, meaning that variations in intensity (air density) are parallel to the wave s direction of travel. This is unlike light or water waves (transverse) that have variations perpendicular to the direction of the waves travel. Sound pressure that moves through the air, not the air that moves. Pure tones- the simplest form of sound wave. All other sounds are made up of combinations of pure tones. Amplitude- difference in sound pressure between high and low peaks of wave.