It could be possible that the hero's shade "existed" in skyloft waiting to be born as the hero of time in ocarina of time. That's because--as youtube referred to--that the howiling stones in twilight princess all had two things:1) sheikah stone symbols, and 2)similar sounds emitted from the ocarina. Mainly because the hero's shade was brought into the world to make the sheikah stones known to everybody besides hylians, because sheikah stones were already created by past cicilizations, according to the goron explorer of the surface's past.