I’ve recorded a few instances of poxbursters getting to detonation distance before they make a noise; giving you less than a second or two to register they’re there.
You can listen to it on any headphones/speakers, and afaik it’s the same (I alternate between a soundbar and beyerdynamics).
There might be an argument for saying the sound chip can’t process enough separate audio streams, but given as I bet we’re all on mobo chips that’s more a software design issue than hardware fault.
I suspect that at times there’s no obvious priority between sounds - if everything is trying to hit you then what do you play to the user and what do you suppress? Which I think came out of patch 13, as mentioned above, when they ramped up the number of Elites in packs.