I just started having audio issues within the past week. This is most obvious when watching a video in any browser. There will be a very brief pop/crackling sound and the audio will be slightly out of sync from the video (I also experienced these popping sounds when talking to friends via VOIP applications). This popping will repeat every minute or so and continue to cause the audio to go out of sync further with each occurrence. Pausing/playing the video will re-sync the audio and video, but of course this would get annoying to do every minute. I resorted to a reboot of my computer, which would prevent the issue from happening again for about a day.
After a few days of dealing with this, I noticed that it was malwarebytes possibly contributing to this issue. Whenever the popping sound happened, I noticed a slight spike in MBAM service's CPU usage (the CPU usage itself was not unusual, just the fact that it happened the exact moment of every popping sound). After some trial and error, I came to the conclusion that it was something to do with the web protection. I toggled the web protection off and back on, and this would stop the popping sound/audio sync issues for about a day.
I will try the steps AdvancedSetup posted earlier to help with tracking down this issue, but I don't know how much help it would be. I see mention of Realtek audio drivers, which I also have (motherboard is an ASUS Z170-A -- using onboard sound). Maybe that is our problem, although I have no idea what changed for me to start having this issue... I did not update any drivers.