Attenuation is a process whereby sound energy is extracted from a wave by which three mechanisms?

Attenuation is a process whereby sound energy is extracted from a wave by which three mechanisms?

• A. Absorption, Scattering, and Diffraction
• B. Absorption, Refraction, and Diffraction
• C. Absorption, Scattering, and Reflection
• D. Scattering, Refraction, and Reflection

Answer: (C)

Attenuation is the reduction of sound energy as it travels through a medium. The three mechanisms that remove energy from the forward-propagating wave are absorption, scattering, and reflection. Absorption converts acoustic energy into heat within the material, more pronounced at higher frequencies. Scattering redirects energy away from the forward direction when the medium has small inhomogeneities, so the forward intensity drops even though some energy still propagates elsewhere. Reflection occurs at boundaries where part of the energy bounces back toward the source, reducing what continues forward. Diffraction and refraction can bend or spread energy, but they do not by themselves remove energy from the beam; they redistribute it. Hence, the energy-removing processes are absorption, scattering, and reflection.

Attenuation is the reduction of sound energy as it travels through a medium. The three mechanisms that remove energy from the forward-propagating wave are absorption, scattering, and reflection. Absorption converts acoustic energy into heat within the material, more pronounced at higher frequencies. Scattering redirects energy away from the forward direction when the medium has small inhomogeneities, so the forward intensity drops even though some energy still propagates elsewhere. Reflection occurs at boundaries where part of the energy bounces back toward the source, reducing what continues forward. Diffraction and refraction can bend or spread energy, but they do not by themselves remove energy from the beam; they redistribute it. Hence, the energy-removing processes are absorption, scattering, and reflection.