Windows 10 audio problems with headphones

First off, I'm sorry if I'm describing this poorly and if you have any questions I can try to answer in the comments.

Anyways, for a while now my (Dell) computer with Windows 10 has had issues with playing audio through headphones. The headphones work fine with my phone and on a chromebook, so this problem isn't particular to them.

What happens is that while I'm watching a video the volume will shift between a louder, more robotic level and a normal one. The actual volume display doesn't show any change, and in addition the audio has a tendency to 'tear' (for lack of a better word; the sound gets incredibly distorted) every once in a while.

I've done a fairly shallow search on the subject but couldn't find anything that helped; any ideas on how to fix this?