That's a rather weird noise. Generally valve train related noise is a pretty regular noise. Kind of like "tick" "tick" "tick".
Not "tick"...."tick".........."tick".."tick"...
A mechanic stethoscope is very useful to help pinpoint where the noise is coming from. Knowing this helps reduce the guess work diagnosing what's going on. I'm sure when you take the car in the tech will use this unless it is clear to him where the noise is coming from.
Being that I'm not at the car and unable to confirm where the noise is coming from from just the clip that sounds more like an accessory drive noise. With the engine off check the accessory belt for any signs of degradation. With the engine running at idle and a bright light watch the belt to see if you can spot any abnormal movement.
With one of my cars after a brief stop to buy some food off a lunch truck when I restarted the engine I heard an irregular tick. Nothing appeared to be wrong, no warning lights, or messages, engine vital signs were ok, and I drove the car the couple of blocks to the office. Later in the day I restarted the engine and the noise was still present. Had the car flat bedded to the dealer. At the dealer the car was rolled off the truck. With SM and senior techs around I started the engine. Crickets.
Senior tech did a thorough check out of the accessory drive and found nothing. I took the car on a 30 minute test drive -- which duplicated the 30 minute drive to work -- and was unable to make the noise reappear. SM and tech told me that what probably happened is some trash got blown up and caught in the belt. Told me they see this with other cars maybe 6 times a year. Not common but not unknown either. In the case of my car the air blast the car was exposed to while on the back of the flat bed probably dislodged whatever it was that got caught.
There is another possible explanation though I don't know if this is plausible with your engine but there have been a few cases where something gets caught in the crank pulley and as the engine runs and this something rattles around inside the pulley cavity it makes an irregular "ticking" noise. In one case an owner found a small bolt caught. But a small rock can do it too.