sound transmission classes
The speed of sound in air increases with temperature and slightly with humidity and pressure. Higher frequencies travel very slightly faster than lower frequencies. In air at sea level, 60% humidity and 30°C, it is 344 meters per second. The U. S. Standard Atmosphere (1976) sets the speed at sea level and 15°C to 340.3 meters per second.
The speed of sound in water, at 30°C, is 1509.5 meters per second, and in seawater, 1546.2 meters per second.
The speed can be much greater in solids. In a beryllium rod whose diameter is much less than the sound's wavelength, sound reaches a speed of 12,870 meters per second, perhaps the highest speed in solids.
Copyright © 2002 Sizes, Inc. All rights reserved.
Last revised: 17 December 2002.