It’s not like voices. At least not most of the time. It manifests in so many different ways.
The “default” is best described as thoughts – not streams, more like a word cloud: there’s no order, there’s more than one and it’s not linear. When I say thoughts I mean ideas, notions, impulses – sometimes so raw they aren’t even in words yet. It’s like the murmur of a crowd, it’s so varied and uncoordinated the only way to make sense of anything is to pay attention to the voice of one person at a time. Perhaps like a microphone that is passed around. Now imagine random hands flying out of nowhere trying to grab it whilst random heads fly past trying to shout into it whilst you are trying to explain something. That’s what it feels like when I’m trying to concentrate.