This is still happening in the latest 1.21.51, I've tried on 3 different PCs / Laptops, with and without headphones, it's happening to me on all of them.
For some reason it doesn't happen on my mobile phone, Java edition also works fine on the same devices.
Actually you are correct, that seems to be the issue, I just tested it.
It looks similar but for me even without turning my head in certain positions the sound is choppy, even if I'm just running straight
Although the choppy sounds in that bug report sound the same as mine
I've figured out why it's happening.
If you have audio enhancements enabled on your speakers or whichever audio device you are using, it will cause this glitch, if you turn it off it goes away although the audio of your entire device will be muffled and not sound good, it's not ideal to have to turn this off for Minecraft audio to work properly.
You can find this setting in Settings -> Sound -> More Sound Settings -> Click on your audio device and go to it's properties -> Advanced and the option should be at the bottom.
I hope with this information the actual bug itself is able to be resolved. It's been there for years.
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