Hi Falgn0n,
God the Father does not speak, as the person of Jehovah/Christ is His spokesman/voice in the OT. When Christ was on earth it would have been the voice of an angel as Brenda said. So as with somebody like Samuel or any of the Prophets, I would assume it would have been Jehovah.
But there is a vast spiritual world and their mode of communication is direct to our mind. I think it will be shocking when we finally learn the extent of the spiritual realm.
But we also have our own inner voice/spirit - our conscience.
Rom 8:16 The Spirit Himself bears witness with our spirit that we are children of God,
I use my inner voice to talk to myself all the time, as I like to think about something before I actually say it. Maybe that is what the spirit world tries to speak to or influence - our conscience, to make us think a certain way.
1John 4:1 Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world.
v. 2 By this you know the Spirit of God: Every spirit that confesses that Jesus Christ has come in the flesh is of God,
v. 3 and every spirit that does not confess that Jesus Christ has come in the flesh is not of God. And this is the spirit of the Antichrist, which you have heard was coming, and is now already in the world.
v. 4 You are of God, little children, and have overcome them, because He who is in you is greater than he who is in the world.
v. 5 They are of the world. Therefore they speak as of the world, and the world hears them.
v. 6 We are of God. He who knows God hears us; he who is not of God does not hear us. By this we know the spirit of truth and the spirit of error.
mercy, peace qand love
Kat