Britannica
Sources used in this answer
Why does a voice sound muffled when heard around a corner?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
acoustics
Artificial omni-directional sound source in an anechoic acoustic chamber.
A voice sounds muffled when heard around a corner due to the physics of diffraction.
Diffraction is the capacity of sound waves to bend around obstacles. However, this ability is dependent on the wave's wavelength and frequency. Lower-frequency sounds have longer wavelengths and bend around corners more readily than higher-frequency sounds, which have shorter wavelengths.1
Because the higher-frequency components of a voice do not diffract as effectively as the lower-frequency components, they are blocked or attenuated by the corner. Consequently, the sound reaching the listener is dominated by lower frequencies, resulting in the characteristic "muffled" quality.1