One of the many side benefits of sound art are the audio documents left behind after the exhibit closes — or, for that matter, that are circulated while the exhibit is still happening. Over at the Touch podcast spinoff, touchradio.org.uk, Philip Marshall has made available an edit of his piece “Ghost.” It’s a mysterious mix of digital music and spoken fragments, amid swaths of field recordings, the latter replete with wind-blown microphones, a smattering of rain, and all manner of passing fragile incidents (MP3). The work is intended to be heard as part of “The Space Between Seeing and Knowing Is Haunted,” an exhibition curated by D”“L Alvarez at two Berlin galleries (Exile thisisexile.com; Arratia, Beer: arratiabeer.com). The spoken material originated on The Ghost Orchid: An Introduction to EVP, a collection of “electronic voice phenomenon” examples. The rain was provided by Dale Cornish (baraclough.co.uk) — at least, the recordings of the rain were.