• Sound is produced by a vibrating source that causes the matter
around it to move.
• No sound is produced in a vacuum - Matter (air, water, earth)
must be present!
• The vibration of the source causes it to push/pull its neighboring
particles, which in turn push/pull its neighbors and so on.
• Pushes increase the air pressure (compression) while pulls
decrease the air pressure (rarefaction)
• The vibration sends a wave of pressure fluctuation through the air