Just came accross this tidbit.
Chris Strachwitz, Arhoolie Productions, president, discussing the origins of his Arhoolie Record label.
"I had thought of names like Delta, Gulf, Down Home, etc., for my label when Mack McCormick suddenly suggested ARWHOOLIE! My initial response was: "AR what?" But soon the name, at least a part of which apparently means a field holler, seemed rather appropriate for the music I wanted to record. The word, spelled as above by the recordist, appeared on a Library of Congress recording made in Mississippi and apparently was the response of the singer when asked what he called the selection just recorded. I have since heard the word "hoolie" in reference to a field holler but I think the "ar" in front of it was simply the man stuttering a bit in Mississippi fashion when somewhat nervous!"