Also known white sound, it is a random selection of pure waves at all frequencies at equal power. The result is a “hissing” noise such as can be heard on TV stations that are not broadcasting or between radio stations on the AM band. It is frequently used as background noise during EVP, giving unembodied spirits the equivalent of vocal chords with which to communicate. It is also used in some paranormal experiments to block out unwanted sounds, as well as in some systems designed to isolate people from unwanted aural input. In actuality, due to the nature of hearing, to practically obtain the effect of white noise the relative volumes of the higher and lower ranges needs to be modified as what is known as “pink noise.”