# Perception of sound in varying temperature

If one disregards situations like explosions (where air is heated) etc. and also disregards humidity – does temperature affect sound in any way for the observer?

Say for example one listens to a song/speech/sound from a loud speaker in 40°C and the same in -50°C.

$$v_{40{^\circ}{\mathrm C}} = 331\tfrac{m}{s} \sqrt{\frac{313\,{\mathrm K}}{273\,{\mathrm K}}} = 354\tfrac{m}{s}$$

$$v_{-50{^\circ}{\mathrm C}} = 331\tfrac{m}{s} \sqrt{\frac{223\,{\mathrm K}}{273\,{\mathrm K}}} = 299\tfrac{m}{s}$$

Where K is Kelvin

Would there be any difference in the perception of the sound?

From what I understand there is no change in frequency or amplitude due to temperature, but I'm having some trouble grasping how such big changes in speed of sound would not affect the perception of the sound.

## 1 Answer

Sound in free space:

The crucial issue is not of temperature, but of temperature gradients. Hot and cold environments with well-mixed air do not have much impact on sound propagation. When there are layers of air with different temperatures, refraction occurs.

Different frequencies are subject to attenuation according to Stoke's law.

Closed-space and half-space acoustics:

Reverberation constants change with temperature, while wall absorption doesn't. Hence, a hot and humid room will exhibit a different reverberation pattern from a cold and dry one.

• Thanks. Believe I'm closer to a understanding of various concepts trough reading up on provided terms. – user129107 May 5 '14 at 22:01