I think most of us have heard that voice. I call it the reptile, some folks call it an addict voice or AV, it's part of addiction - our brain's way of saying, I want you to restore my chemical (im)balance that you've gotten me accustomed to. Earlier on, that same (im)balance is responsible for withdrawal symptoms ranging from jitters to full-blow DT's and hallucinations and seizures, but eventually it quiets down to just an annoying little voice.
Mine is long quiet now, so it does go away, but it takes time.