Acoustic Impedance Reflection

When a sound wave travels from one medium into another, a portion of the wave is transmitted while the rest is reflected. The specific acoustic impedance of the medium dictates how pressure and particle velocity match up at the boundary.

Experiment

Explore how varying impedances changes the reflected and transmitted waves in the Acoustic Impedance Reflection module.

1. Set Specific impedance 1 to 1 and Specific impedance 2 to 4.
2. Set Incident pressure to 1.
3. Observe that the pressure reflection is 0.6 and the pressure transmission is 1.6. Notice that the transmitted amplitude can exceed the incident amplitude without violating energy conservation, because the impedance ratio scales the energy.
4. Swap the impedances: set Specific impedance 1 to 4 and Specific impedance 2 to 1.
5. Observe that the pressure reflection becomes -0.6, indicating a phase inversion of the reflected wave. The energy reflection remains 0.36.