WD Ultrastar DC HC530 14TB - sound of a train on the tracks

I have a 3 month old Western Digital Ultrastar DC HC530 hard drive, 3.5 "- 14 TB and makes strange deep regular sounds at rest.
Not only in the NAS but also just connected to the power supply. Regularly every 5 seconds. Is this normal? Please help.
Sample here:

https://youtu.be/-yYSB4MFbwQ