The source of every sound is a vibrating body Take for example The vibrating drum head pushes against the air every time it moves outward We call these pulses of compressions and rarefactions P-P-P-P-P-P-Pressure waves A drum Each sound has a distinctive pitch, loudness, and quality Waves which your ears pick up and analyze But first let's investigate what causes sound The source of every sound is a vibrating body Take for example A drum The vibrating drum head pushes against the air every time it moves outward We call these pulses of compressions and rarefactions P-P-P-P-P-P-Pressure waves The vibrating drum head pushes against the air every time it moves outward We call these pulses of compressions and rarefactions P-P-P-P-P-P-Pressure waves It's these vibrations which your brain interprets as sound Pressure waves