Explain how the absorption of sound waves differs from the transmission of sound waves

When a sound wave meets an obstacle, some of the sound is reflected back from the front surface and some of the sound passes into the obstacle material, where it is absorbed or transmitted through the material.

Reflection and absorption are dependent on the wavelength of the sound. The percentage of the sound transmitted through an obstacle depends on how much sound is reflected and how much is absorbed. We are assuming that the obstacle is relatively large, such that no sound passes around the edges.