Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025
Definition
The intensity reflection coefficient is a measure of the fraction of incident acoustic wave intensity that is reflected at the boundary between two different media. It is a dimensionless quantity and ranges from 0 to 1.
The intensity reflection coefficient depends on the acoustic impedances of the two media involved.
It can be calculated using the formula $R = \left(\frac{Z_2 - Z_1}{Z_2 + Z_1}\right)^2$, where $Z_1$ and $Z_2$ are the acoustic impedances of the first and second medium, respectively.
A higher difference in acoustic impedance between two media leads to a higher intensity reflection coefficient.
In medical ultrasound, understanding this coefficient is crucial for interpreting images since it affects how much sound is reflected back to the transducer.
The sum of the intensity reflection coefficient and the intensity transmission coefficient equals one.