1. waves
1.1. transverse/compression
2. SPEED?
2.1. in gas
2.1.1. 1500m/s−1
2.2. in liquid
2.2.1. 330m/s−1
2.3. in solid
2.3.1. 6000m/s−1
3. properties
3.1. wavelength
3.1.1. defenition
3.1.1.1. is the spatial period of the wave – the distance over which the wave's shape repeats
3.1.1.2. it is determined by considering the distance between consecutive corresponding points of the same phase
3.2. amplitude
3.2.1. Peak-to-peak amplitude
3.2.1.1. is the change between peak (highest amplitude value) and trough (lowest amplitude value, which can be negative)
3.2.2. Semi-amplitude
3.2.2.1. semi-amplitude means half the peak-to-peak amplitude
4. direction of sound
4.1. defenition
4.1.1. Direction is the information contained in the relative position of one point with respect to another point without the distance information.
5. definition of sound
5.1. sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies
6. audibility
6.1. human
6.1.1. 20kHz and 200kHz
6.2. animals
6.2.1. rat
6.2.1.1. 200-76,000
6.2.2. elephant
6.2.2.1. 16-12,000
6.2.3. tuna
6.2.3.1. 50-1,100
6.2.4. owl
6.2.4.1. 200-12,000