In acoustics, white noise is a sound that has equal intensity at all frequencies. This means that the sound does not have any specific pitch or tone, and it sounds like a hissing or rushing sound. White noise can be used to mask other sounds, such as traffic noise or conversations, and it can also be used to soothe babies.
White noise is also used in telecommunications to provide a reference level for measuring signal strength. In this context, white noise is a signal that has a constant power level across a specified bandwidth.