Noise

Sound propagation

The propagation speed or velocity of sound depends on its nature, as well as its temperature and pressure.

In vacuum, sound does not travel because there is no matter to carry the waves. Sound insulation uses this property.

Propagation speed depends on the nature of the medium

Materials (20°C)Speed in m/s
Air 344
Water 1 460
Glass 5 300
Steel 5 400
Hard PVC 2 400
Concrete 3 100
Granite 6 200
Vacuum 0

We know that some marine animals (dolphins, whales, etc.) communicate underwater using sounds. The whale song for example, is between 15 and 20 Hz. Research has shown that the whale song travels more than 3000 Km.

Propagation speed depends on the ambient temperature

The warmer it is, the better the propagation.

Temperature in °CSpeed in m/s
- 10 325,4
- 5 328,5
0 331,5
+ 5 334,5
+ 10 337,5
+ 15 340,5
+ 20 343,4
+ 25 346,3
+ 30 349,2

Propagation speed depends on the pressure of the medium

Sound travels less effectively horizontally than at higher angles, due to the change in density. This property has been taken into account in the design of outdoor theaters since antiquity.

 

HearingProTech is a department of Arta Group. Its mission is to perform and disseminate research, analyses, and tools to aid in the selection of personal hearing protection devices. Composed of technical and scientific experts, HearingProTech aims to advance knowledge in this area and make it more easily accessible.