I would not use the 1/2" homesote between the oak flooring and the
3/4" subfloor. Homesote is paper based, soft and flexible. This can put the integrity of your hardwood floor installation at risk.Put your money into a quality 3/4" or thicker rigid subfloor that is properly fastened and glued to the floor joists. Use soundproofing in the joist cavities between floor and ceiling below paying close attention to any cracks or holes where air can infiltrate into the room below. Sound travels through cracks and is transmitted by moving surfaces. If your new floor is very rigid, it will not transmit much sound.
If funds are not a big obstacle, get open cell foam insulation sprayed in the joist cavities. This type of insulation totaly seals air infiltration and provides very good sound deadening.