"Anyway, there is no ‘explanation’ for the widespread abduction epidemic—it is not a problem to be solved but rather a mystery to be entered"Harpur also has a new book: The Complete Guide to the Soul. Harupur's Daimonic Reality is a fantastic book, I think, along with George Hansen's Trickster and the Paranormal, these are two books any Fortean junkie or UFO researcher needs to read.
An interview with Harpur from 2007 for the Dreamflesh Journal, very enjoyable and insightful.
Thank you to The Daily Grail for the link idea. Speaking of the Daily Grail, Greg Taylor has more on his ideas about sound and the source of liminal, weird experiences like OOBEs, Marian Apparitions, and other strange encounters. He wrote a very good article in Darklore discussing the rushing, roaring, ringing, bells, even singing, heard during these events: Her Sweet Murmur, which you can download for free as a PDF, and expanded with A Mighty Rushing Wind on The Daily Grail.