I can't hear that any better than your earlier recording.
But..............
It does sound like the DVD drive is being actuated and finding no disc in it.
I assume this happens at every boot, but generally not otherwise???
My guess is that you have the DVD drive entered into your boot device order in a position ABOVE the hard drive. So the PC first tries to boot from the DVD for a few seconds before moving on to the next device in the list.
You should find that list in the BIOS.
If you see the DVD above the hard drive in that list, move it down, save the changes to the BIOS and then reboot a few times to see if the noise goes away.
If that's no help, I dunno....other than possibly fans.