Sound masking is the addition of natural or artificial sound (such as white noise or pink noise) into an environment to cover up unwanted sound by using auditory masking. This is in contrast to the technique of active noise control. Sound masking reduces or eliminates awareness of pre-existing sounds in a given area and can make a work environment more comfortable, while creating speech privacy so workers can better concentrate and be more productive. Sound masking can also be used in the courtyards or other outdoor areas to restore a more natural ambient environment

   Sound masking can be explained by analogy with light. Imagine a dark room where someone is turning a flashlight on and off. The light is very obvious and distracting. Now imagine that the room lights are turned on. The flashlight is still being turned on and off, but is no longer noticeable because it has been "masked." Sound masking is a similar process of covering a distracting sound with a more soothing or less intrusive sound.

   Sound masking systems are usually hidden in the drop ceiling, so not only are they out of sight, but also out of mind doing their part behind the scenes.