It is definitely the sound of when the motor of the turntable is turning.
It is connected directly to the laptop with a USB, and the USB connection acts as the electrical supply, so i guess it is running its power from the Laptop.
The noise gets quieter when i turn the volume down, but it has no built in volume or speakers, again it is using the speakers from the laptop.
I do not see any loose cables and the cartridge seems to be in place.
It does indeed hum the moment the platter is spinning.