What is your Blogging Voice?

In my discipline (composition and rhetoric) -can I actually claim a discipline yet, that sounds so scholarly-anyways, in comp and rhet we talk about voice. When students write we ask them to put their voice on paper, with some exceptions of course, or modifications. There are books on how to find your voice and tons of different pedagological approaches. What I notice, in my own writing is that my voice is not consistent, I change things based on the audience I'm writing for. Well, this is a kind of -duh- statement for most folks, but I'm puzzled by the blogging voice.

Some people, myself included, start a blog without a real audience or purpose. I started this blog this past summer because I'd been reading blogs like dooce and academic blogs as well. I wanted to find a way to put my thoughts out there, but really didn't keep up with it and I think one of the reasons for that was because no one (aside from a random stranger) was reading my blog. Now, I write in a journal almost every day and I do that religiously even though no one is going to read it, so whats the difference?
--> For me, one difference is that my voice in the journal is not my voice on the blog. My journal voice is much more personal, unreserved, uninhibited, hell who's gonna read it! But, the blog is different, even though I didn't think I had any readership/audience, there was still that chance. And even now, that I have a small circle of blogging friends, I find the same holds true, I write, but I think I have a different voice.

Does my blogging voice sound like my 'real' voice?
And as my dear husband would ask, does it matter?