Hello. This is not a known issue with your model so it could be difficult to track down. Some initial suggestions:

> If you have any device like fingerprint reader, facial recognition, etc, -- those can produce random clicking noises.

> if running on battery power see if you get the noise when plugged into house current.

> try using the native Windows driver as a test. To install the native driver, remove the Realtek driver. Open the Device Manager and expand "Sound, video and game controllers". Right click on the Realtek and select to uninstall. Put a check mark in the option to delete the files, and then ok. When you reboot, Windows will either install its own native driver or another Realtek driver if there were any other versions on the hard drive. So go back to the Device Manager and check for a Realtek driver. Keep uninstalling & rebooting until Realtek no longer appears under Sound Controllers and "High Definition Audio Device" appears in its place.

If you still get the noise with the native driver then you can rule out the Realtek driver as the cause of the problem.

I have exactly the same issue on an E6440.  It would be nice to know how to resolve this, as it is annoying.  Oddly, if you play a sound that makes the clicking noise, such as the Windows default beep, it will lessen each time you play it successively, until it doesn't happen again.  This doesn't mean that another sound won't have the same behavior though - it will.  

I have exactly the same issue on an E6440.

Does it show the same behavior as described on the other thread where you posted, with the pop only coming through the speakers and not through the headphone jack?

If it does that, and does it with both the vendor's audio driver and the Windows native driver, I would say that combination strongly points to a hardware defect.

Have you contacted tech support about getting it fixed?