Am I hearing spirits?

When i was younger around 7-8 years old i would hear church music kind of like a church choir (nobody singing just music) while i was trying to go to sleep but it wasnt every night i would hear this. Me and family moved to another state when i was around 13 and i didnt hear anything until i was about 15-16 years old. I would lay in bed and it always sounded like a man singing lullabies to a baby but i would just shrug it off and try to go to sleep and that happened almost every night and at that point i really thought i was going crazy until a friend spent the night and asked me who was singing to a baby so when she told me that i figured i wasnt going too crazy and if i was then she was too but as i got older that stopped and it went to hearing pieces of people talking like 4-5 people talking at once but not to me and not to each other. One night not too long ago i was laying in bed reading a book when i heard two men talking to each other (im 25 now, married and not in the same house as i was when i was 15-16 years old) i didnt see anybody and nothing was said to me and i could barely even hear what they were saying. It was like they were whispering. I have looked up stuff about mental illness and they all say the person hears voices and some times have conversations with what they are hearing or what they are hearing it talking directly to them. I have never had any of that happen with me and i have never tried talking to anything i hear because for one they are not talking to me and second i find it silly and a little crazy to try to do it anyway. So can someone tell me whats going? Am i hearing spirits? And could someone please explain why and how my friend heard the same thing as i did when i had never told her? And how my step-son heard the same thing when he was staying at my mothers in my old room and i have never mentioned anything like this around him?