Final answer:
A sound wave starts as a vibration, travelling through an elastic medium, like air, and experiences loss of energy over time, primarily due to thermal dissipation, in a process called damping.
Step-by-step explanation:
The phenomenon that begins as a vibration, travels through an elastic medium, and loses energy over time is known as a sound wave. For instance, when a vibrating string produces a sound wave, part of the string's energy goes into compressing and expanding the surrounding air, creating regions of higher and lower pressures called compressions and rarefactions. These pressure waves move through the air as longitudinal waves with the same frequency as the vibrating source.
Furthermore, as a speaker produces a sound wave, it similarly causes alternating patterns of compressions and rarefactions in the air, which also propagate as longitudinal pressure waves. However, during the transmission of sound, some energy is invariably lost as thermal energy due to factors such as turbulence and interaction with materials in the environment.
In simple harmonic motion, energy oscillates between kinetic and potential forms without loss, contrasting with sound transmission where energy is gradually dissipated. The loss of energy in sound waves, primarily through absorption and thermal conversion, results in a decrease in wave amplitude, a phenomenon known as damping.