I cannot really give you advice, because it is something you will have to learn on your own together with the Lord. But I can share my experiences.
When the Holy Spirit speaks to me, it's usually not an actual voice, although He has spoken audibly to me a few times. (Just small things, no major revelation). It's more of a "movement" in my thought patterns, if that makes sense to you. Some people call it an impression. The Holy Spirit dwells in our innermost being, so it feels like He speaks from deep within. It always feels wonderful, safe, warm and comforting, and most of all true and pure. Except when He convicts me, He can sound pretty harsh, but I still feel loved. Usually He just changes my understanding, but I have learnt how to listen to it more intently, meaning my brain translates the impression into words. God's voice will ALWAYS correspond to the Bible. God cannot lie. And He never uses fear, only love.
The subconscious for me usually sounds like my friends and family, or like my own voice. Like my brain is just picking up memories. It's also a bit more scattered.
I have been oppressed and tormented by demons, and they tend to speak more audibly. The voices are usually very clear and easy to hear, and sounds like they come from the outside. They don't always sound frightening, sometimes they sound really pleasant, but they always sound like strangers. If it feels wrong, it is never God.
John 10:3-5
John 10:27
Everyone who has the Holy Spirit can hear His voice, but it isn't easy. It takes a lot of practice, and you will probably be fooled by Satan a couple of times. God will forgive though. Pray for God to increase your discernment, and ask Him to teach you how to listen. He wants us to listen to Him and follow Him personally.