"Using methods employed in criminal investigations, the Japan Acoustic Lab has analyzed the skeletal structures of Leonardo Da Vinci and Mona Lisa's faces to replicate how their voices would have sounded."
"We believe we were able to create the voices that are very close to the real voices. Perhaps it was really how they really sounded," the lab's chief Matsumi Suzuki says on the website.
In another report, freeinfosociety has great historical persons and sounds, for free,in MP3 Format (include Thomas Edison, Albert Einstein, Robert Frost, etc)
Maybe a new sample library with historic voices? Einstein singing "Mona Lisa" or Da Vinci rapping the Da Vinci code. Think of the possibilities.