* Temperature and Molecular Motion: Sound travels as vibrations through a medium. The speed of sound is directly related to the speed at which these vibrations propagate. Higher temperatures mean molecules are moving faster, leading to quicker transmission of vibrations.

* Lower Temperature, Slower Molecules: As the medium cools, its molecules slow down. This means the vibrations caused by sound waves travel slower through the medium.

Example: Sound travels faster in warm air than in cold air. This is why you might notice sounds seeming to carry farther on a warm day.

Important Note: This principle applies generally to gases and liquids. In solids, the relationship between temperature and the speed of sound can be more complex due to factors like the material's structure and how it changes with temperature.