Note: The phone call from Night Five is not actually spoken by Phone Guy. It's more likely one of the animatronics in a deep, garbled, demonic-sounding voice. When the audio clip is played backwards and some post-processing applied, it is rendered into a difficult to understand, and hard to translate, garble.
While numerous possible fan translations exist, a more recent speculation is that the call is in fact an excerpt from the book Autobiography of a Yogi by Paramhansa Yogananda. It has not been confirmed, however, and is simply speculated because of the frequent matches in hand-translated phrases that most translators of the call have found. The complete passage speculated to be in the call is as follows: