Nocturnal Emissions is a sound art project that has released numerous records and CDs in music styles ranging from electro-acoustic, musique concrete, hybridised beats, sound collage, post-industrial music, ambient and noise music. The sound art has been part of an ongoing multimedia campaign of guerrilla sign ontology utilising video art, film, hypertext and other documents.

The project was initiated in London in or around 1980 by Nigel Ayers together with collaborators Daniel Ayers and Caroline K. Numerous other members have come & gone. Now based in Cornwall, on a nodal point on the Mary-Michael Ley, the mission continues in some kind of polytantric union with the multiple personalities of one solo member and a cast of thousands.