What Causes Pinging Sensation In The Brain After Stopping Ambien Tablets?

I am having brain pings left side top of my head every 10 to 30 seconds, very annoying. It started yesterday afternoon, I slept not so good as to it kept waking me up. I was on a generic Ambien but stopped taking them 3 to 4 weeks ago, I have taken over the counter sleep aid from Walmart since then. Is the weaning causing these pings and if so how long does this last??? Cathy