From Allmusic.com : "Bang!, the first Hafler Trio album, was released in 1984 and is reissued here with some additional tracks from the same period, some previously unreleased and some released in 1985 on a limited-edition Japanese cassette. The album contains three different types of material. The first is somewhat harsh ambient music, similar to their future direction. Some of the tracks, such as "The Morality of Sound" and "Psychophon Installation Test Tape," sound like untreated recordings of people moving about in rooms. Several, including "Owl Ionisation Recording," center around bird noises. Still others, such as "BANG!" and "Location Screening Exercise," use voice loops, but treated beyond the point of recognition. Second, there are news and radio broadcasts, looped and layered so that the voices and texts are often still recognizable. All of the material from the original release (tracks one through 15) is of these two types (although the opening moments of the CD include someone answering the phone at ROBOL). However, the supplemental material for the CD reissue include interviews and a demonstration cassette designed to encourage the fiction that the Hafler Trio was part of a research organization, ROBOL, working with controversial scientist Dr. Robert Spridgeon on issues relating to perception. There is even a straightforward albeit tantalizing interview with Dr. Edward Moolenbeek on his role in various experiments with ROBOL, the Hafler Trio, and Dr. Spridgeon. The liner notes and track titles also contribute to this fictional understanding. The album's overall effect is a spectrum of recognition, from overt to subliminal, and the relative brevity of the tracks makes for an overall disorientation, requiring more active listening than the group's later works."
"Bang! An Open Letter" was released by Doublevision in 1984, then re-released by The Grey Area in 1994.
Get it here : The Hafler Trio - Bang! An Open Letter