This issue has impacted me for years but I used to be able to fix it by restarting my computer. This is no longer the case.
When I join any game, early game sounds (ACU build sound, unit select sound, et cetera) play once, then never again for the rest of the game. Sounds later in the game, such as pings and strategy launch notices, never play.
All steps discussed here: https://forum.faforever.com/topic/796/i-can-t-hear-some-of-the-audio-or-other-sound-issue-what-should-i-do/3
Uninstalling sound drivers
Deleting game.prefs file
I use mic-less headset in Aux port and Razor Chrommo speakers in USB port, software switching between the two sometimes.
Windows 10 Home, 64 bit.
Thoughts or steps to fix? Really, I'm at my wit's end here.
I would try removing as many USB devices as possible (in your case Razor Chromo) and try if that works. USB devices include their own sound card as well as sound driver and i suspect the game might not like that. So try with Aux only. And maybe fully uninstall anything related to your USB audio device.