If you couldn't process multiple streams ( audio/visual/other senses ) how would you ever be able to monitor the background for danger and context switch?
There is a difference between conscious experience and what's going on in the background.
This is about multiple speech streams.
More specific from the mere ability to process multiple sensory streams in general.
There is also a different quality of processing. Textunderstanding and danger deciphering of signals.
There’s a big difference between processing multiple streams, and processing multiple streams simultaneously.
You can achieve the former, without the latter, by doing time slicing. Spending a small amount of time processing stream A, then dropping that and processing stream B for a moment, then swapping back. Just like how a single core CPU can process multiple threads.
Proving the brain is continuously processing and encoding multiple streams simultaneously is an interesting finding that helps us better understand how our brains handle multitasking. That’s absolutely something worth studying and understanding, even if the headline discovery “feels” obvious. It the precise mechanism that’s interesting, not the effect the mechanism produces.