[kccqzy]

I'm an introvert, hates social gatherings, etc. Yet I've found the ability to think aloud extremely helpful. Sometimes just vocalizing my thought makes the thinking clearer, almost as if hearing myself again makes the brain think over every thought once again. In a collaborative situation (such as pairing) this is even more helpful.

[michaelcampbell]

I believe it does exactly this. The rise of "rubber duck" debugging is a tool to extract this sort of thing, in fact.