Sound waves are mechanical longitudinal waves requiring a medium for travel, exhibiting faster speeds in denser materials. With sound moving quickest through solid steel (5920 m/s) and slowest in gases, the velocity in air stands at about 343 m/s and 1480 m/s in water. These waves, consisting of compressions and rarefactions, vary in loudness according to the amplitude of vibration. Acoustics, the study of sound, underscores that sound cannot propagate in a vacuum and highlights the human audible range from 20 Hz to 20 kHz. Sound's speed is influenced by the medium's properties, making its study essential in understanding acoustical phenomena.