Sound waves are caused by vibrating objects. When an object vibrates, it sets the particles in the surrounding medium (such as air, water, or solids) into motion, creating pressure waves. These pressure waves consist of alternating compressions (where particles are pushed closer together) and rarefactions (where particles are spread further apart). The vibration transfers kinetic energy to nearby particles, which then pass this energy along, propagating the sound wave through the medium
. The particles themselves do not travel with the wave; instead, they oscillate back and forth around their equilibrium positions, allowing the energy to move through the medium without the particles permanently shifting location
. This chain reaction of particle vibrations is what produces the sound waves we hear. In summary, sound waves are caused by the mechanical vibrations of an object, which create pressure disturbances that travel through a medium by particle-to-particle interactions
