My other half and I are both experiencing the same issue since Endwalker release and it's driving us nuts - given the effort that has been put into the audio of this game it's really disappointing to have it ruined by this issue.
I've tried playing the game with different audio devices which include:
Speakers (AUX)
Wired headset (USB)
Wired headset (AUX)
I've tried adjusting the different settings as suggested on a couple of Reddit threads:
Run in DX9
Change listening position (tried both extremes of 100% Camera and 100% Character)
Lower audio quality (all the way down to 16bit 8000hz - Telephone quality)
I have found that as soon as I get the stuttering, simply turning the camera in different directions can reduce it - I think this gives even more evidence that it's the sound engine changes they've made for the spacial audio.
The issue still persists and I believe it needs to be officially accepted by the developers as a known problem that is caused by something they have adjusted and not try to shift this onto an issue with users hardware.