I'd say it's the "voices of the other side". I've been experiencing much of that prior to OBE and with time have learnt that it's best to ignore it. There is a lot of beings who are not interested in us evolving and experiencing and do their best to scare those who want to try something different than the ordinary 3D life. Loose the fear and send them some love - they'll dissapear in no time.
Good luck!
