Noise can be introduced in various ways.
You may refer to this article to troubleshoot.
You might also test the Main L/R outputs. Test different headphones. Test your headphones on another device.
Try also connecting your Studio 192 to a different USB connection and with a standard USB 2.0 cable.
You can open Universal Control, click the image of the 192 to show the mixer view. Click the setting wheel in the upper right hand corner and Bypass Mixer. Test this for noise.
If you still have noise, connect and test your 192 on a different computer.
You may also need to contact PreSonus Support for further.