Very interesting, thanks. The processed vocals may be Hoshino himself singing, or at least it's sort of implied here:
http://www.myspace.com/kotahoshino0423. He even has lyrics for some songs there.
His other works like Evergrace and Metal Wolf Chaos also use these vocals, and maybe others, unfortunately many of From Software's games don't get official OSTs.
I also think Drag-on Dragoon 1 would make an interesting read, though certainly it won't win any popularity contest (pity...).