There is now a long clip on YouTube from the TV show mentioned in my last post, Academy Night.
This clip, which is the first part of the show, has Omigawa Chiaki walking around the part of Tokyo that Soredemo Machi ga Mawatteiru is set in, visiting the grocery store, the fish store, and the cafe (where Yuuki Aoi is waiting). When Chiaki visits the shrine, she prays for a second season for SoreMachi, lol.
I think this gives us a pretty good idea of what her ordinary voice sounds like. Not much like her normal seiyuu voice, but also not as high as the couple of clips I linked to in a comment on that last post.
Following the SoreMachi feature is an Amagami SS feature, interviewing Asumi Kana, who plays Miya.