A stationary sound source is one whose position does not change in relation to the observer. This means that the sound waves emitted by the source travel in straight lines and are not affected by any intervening objects. In contrast, a moving sound source will cause the sound waves to travel in curved paths, and the observer will hear the sound as coming from a different direction.

Some examples of stationary sound sources include a person speaking, a musical instrument being played, or a radio playing. These sources are all considered to be stationary because their position does not change in relation to the observer. However, if the person speaking were to move, or if the musical instrument were moved, then the sound waves would travel in curved paths and the observer would hear the sound as coming from a different direction.

Stationary sound sources are important in a number of applications, such as sound recording, sound reproduction, and noise control. By understanding how stationary sound sources work, engineers can design systems that can accurately capture and reproduce sound, and that can also reduce unwanted noise.