Official comment
The #1 reason for noise over the USB connection is a poorly shielded charging circuit and USB power within the computer. One easy way to illustrate this is to disconnect your computer's power supply - in many cases the noise will disappear or drop, for those where it continues, this shows that the isolation is almost nonexistent.
You can try using a USB cable with a ferrite core, or a transformer-isolation USB cable like this: https://www.amazon.com/SMAKN-Isolator-Digital-Isolation-Industrial/dp/B00XXPO4UG