soul Pronunciation Key (sol)
n.
1) The animating and vital principle in humans, credited with the faculties of thought, action, and emotion and often conceived as an immaterial entity.
2) The spiritual nature of humans, regarded as immortal, separable from the body at death, and susceptible to happiness or misery in a future state.

Like in movies and stories about hauntings....someone dies and didn't accomplish something while they were alive, or had something terrible done to them, which needs to be known or fixed. So their spirit just lingers around waiting to be heard, or to warn someone......i dunno just a thought *shrugs*