If the eyes are the windows of the soul, then the voice is the window opened up and the sound of the soul coming out.
The wonderful beauty of prayer is that the opening of our heart is as natural as the opening of a flower. Just as to let a flower open and bloom it is only necessary to let it be, so if we simply are, if we become and remain still and silent, our heart cannot but be open, the Spirit cannot but pour through into our whole being. It is for this we have been created.