The Doppler effect is an alteration in the observed frequency of a sound due to motion of either the source or the observer. The actual change in frequency is called the Doppler shift. A sonic boom is...The Doppler effect is an alteration in the observed frequency of a sound due to motion of either the source or the observer. The actual change in frequency is called the Doppler shift. A sonic boom is constructive interference of sound created by an object moving faster than sound. A sonic boom is a type of bow wake created when any wave source moves faster than the wave propagation speed.
