- Due to 4 key mechanisms:
1. Reflection
- Reflection away from the transducer when they come into contact with an interface at an angle other than 90°
2. Refraction
- Bending of the ultrasound beam when a beam strikes an interface at an angle other than 90° causing it to deviate
- It is analogous to the appearance of a drinking straw bending when resting in a glass of water
3. Scatter
- Dispersal of a beam when it strikes an interface that is the same size or smaller than its wavelength
4. Absorption
- Absorbtion as heat, reducing the energy of the beam
- Degree of absorption is directly proportional to frequency
