I do the *opposite* of what is being described! I cannot process two conversations, I can't process one conversation with a moderate amount of background noise.
In fact, in my house, the way to irritate me quickly is to have two people talking at once. I go into sensory overload, have to cut everyone off, and start again with one conversation at a time.
For me two conversations I'm in and one with background noise of others talking are very different experiences. I have trouble with the latter which feels as though I'm distracted by trying, and failing, to listen to all the other conversations.
That said, I clearly can filter out speech in some circumstances. I can go to sleep with speech radio or an audiobook on, far more easily than with music. I find it difficult not to attend to music, and to attend to both music and speech simultaneously. Music in restaurants bothers me for this reason. DH is the opposite - he'll sleep or work with music on, but not with an audiobook.
