Sound
by Xavier Chan

1. Loudness
1.1. depends on amplitude
2. Pitch
2.1. depends on Frequency
3. consists of audible frequencies from 20 Hz to 2okHz
3.1. e.g.echoes
3.2. if above 20 kHz
3.2.1. ultrasound
3.3. if below 20Hz
3.3.1. infrasound
3.4. New node
4. frequencies produced by vibrations
4.1. propagated by longitudinal waves
4.1.1. through compression,rarefaction
4.1.2. requires medium
4.1.2.1. affects speed
4.1.2.1.1. Vsolid>V liquid>V gas