Intermittent noise from engine
 

Got this irritating noise which I thought was a rattle at first but when listening to it with the hood popped, not so sure. It happens intermittently as stated; haven't noticed any difference whether driving or idle and it doesn't seem to change based on RPM. Thought it might be a belt or (fingers crossed to the contrary) something to do with the timing chain given the truck I have but idk. Once I figure out how I'll attach a video showing the noise I'm crap at describing things. I haven't had the time to go monkeying around in there but I'll probably take it to my mechanic irregardless I just want some kind of idea of what I'm looking at before I do.

225,908 miles as of making this post. Not due for an oil change for a while; I'm using a synthetic blend. The truck runs just fine I'd just rather not ignore it until I turn into a smear on the pavement somewhere.
The video of noise

Does noise cycle ON~OFF with AC Clutch ON~OFF?

You know what, I didn't even think of that. I'll look at the clutch itself tomorrow before work but I did a little test and it does in fact quit when I turn off the AC, so that's the likely culprit. Didn't even cross my mind lol we live in Florida so it's on 99% of the time. Thanks!