Sound waves can travel faster through solids than through air — more than 17 times faster, in some cases. In a solid, sound waves are able to be more tightly compacted than in air because there is less space between the molecules. Sound waves can travel through steel at 3.7 miles (5.96 km) per second. After solids, sound waves can travel the next-fastest through liquids. For example, sound waves travel through seawater at a speed of about 0.93 miles (1.5 km) per second. Sound travels the slowest through air, about 0.21 miles (0.33 km) in a second.
More about sound: