Sound travels as waves that propagate around obstacles, allowing a person to hear speech even when positioned behind the speaker. These sound waves start as circular waves produced by pressure changes in the mouth and can bend around objects due to their typical wavelength of about one meter, which is larger than many obstacles. Huygens' Principle explains that sound waves emanate from every point on the wave front, creating secondary wavelets that contribute to the overall sound propagation. This principle applies to various types of waves, including sound and string waves, where the primary wave consists of these secondary wavelets. Understanding these concepts requires further exploration of wave equations and experimental observations.