I've just spent several hours trying to get this to work, and thought I'd chime in since I finally fixed it and went through seemingly all the hurdles on the way. Hope this will help someone.

Summarized, the game is EXTREMELY picky with your audio setup.

First I didn't get any sound whatsoever. Tried the solutions posted here already, like restarting, disabling all other sound devices, enabling windows audio enhancements, etc. Nothing worked. (These seemingly worked for some other people on here though, so worth a try.)

Then I started testing different headsets. The one I use normally is USB, and that just does not work in any way in this game for me. Then I tried one that uses the audio jack, and plugged it into the front panel of my PC. That works fine in Windows, but results is no sound in ZOE2. Next I tried a bluetooth headset, via a USB dongle. That miraculously worked! Unfortunately, the sound was extremely crackly.

According to posts on here, you need to have sufficient audio quality for the crackling to disappear. But as I soon discovered, my bluetooth headset has a locked quality, so it seemed I was out of luck. That's when I tried my audio jack headset again, but this time on the motherboard audio jack (behind the PC) instead of the front panel one. THAT for some reason worked.

It was also crackly in-game, so I maxed the audio quality in the sound settings... To my great consternation, it was still crackly. After a lot of trial and error, I finally figured out that the game doesn't just want the quality to be sufficient, it needs to be "just right". That is, not too high, not too low. "24 bit, 48000 Hz (Studio Quality)" is what worked for me. Clear audio with no apparent crackling.

Note that this is all without any VR systems plugged into my PC, on Windows 10.
Kinda ridiculous in this day and age to have to jump through this many hoops to get a game to work, I'm quite disappointed in Konami's efforts.

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So, in short:
If you're experiencing audio problems in this game, try plugging a headset or speaker into the audio jack on the motherboard (backside of the PC) and set the quality to exactly 24 bit, 48000 Hz (Studio Quality) in the sound settings for your device.