Aric Blender
When a sound is created it begins to vibrate. Sound needs a medium to travel through. If a sound wave does not have a medium to travel through than there is no sound. When talking about how fast sound travels one must ask through what. With different mediums for sound to travel through, there will be different speeds of sound.

Sound travels through solids faster. The reason is the particles in a solid are tightly packed together which allows the sound to vibrate more. Sound travels through gases a lot slower for the same reason. In a gas the particles are spread out. This makes it more difficult for the sound to vibrate. sound.gif
The sound is able to vibrate through a solid much faster than in a gas. In this picture, the bell is ringing. The sound from the bell is vibrating through the air.

The speed of sound also travels air. In this situation sound travels at faster when temperature in the air is warmer. The speed of sound at 45˚C is 358 m/s. Also at -1˚C the speed of sound is 330 m/s. Speed travels through air with warmer temperature than with a colder temperature. The reason is that the particles in warmer air have more energy which allows the sound to vibrate faster.
Mrs. C states that a sound travels faster through a solid, than in air.

http://www.grc.nasa.gov/WWW/K-12/airplane/Images/sound.gif
http://www.ndt-ed.org/EducationResources/HighSchool/Sound/tempandspeed.htm