While I do not currently keep a nightly journal, I do journal key moments of my life. Besides the event, I like to write out my feelings and to describe my surroundings and sensory perceptions, as relevant. Besides being a writing teacher and tutor, I'm also a writer of creative nonfiction. Many of my essays include memoir, so being able to refer to even brief entries is beneficial.
As for reading these entries out loud for clarity and word choice analysis, I don't recommend editing journal entries. Your journal should be a judgment free zone, a place to write without self-editing.
Actually, for first drafts of any writing assignment I recommend writing freely. Writing is a messy process and sometimes the hardest part is getting started. Part of the reason for this is we often put a burden on ourselves for immediate perfection. Even Tolstoy didn't get it right the first time.
The time for reading out loud and scrutinizing word choice is during revision. This is when the magic happens. It's also during this time that I recommend reading out loud to see where your tongue trips up. Is a comma or word missing? Is the construction of a sentence cumbersome?
If you are keeping a journal, pat yourself on the back. I do wish I was better at doing so on a daily basis. It's a gratifying endeavor that will not only improve your writing, but will be a treasure to one day reread.