When I was trying to figure out the above question I ran across this gem. It says absolutely NOTHING helpful, especially because anyone looking for this advice would not need to be convinced that they need to add audio.
"Instead of writing and typing posts for your personal blog, you can add audio files of you expressing your thoughts and ideas. Here's how to do it.
1. Open your computer's media recorder (Windows Media Player, RealPlayer, etc.) and connect your microphone.
2. Rehearse saying what you want people to hear on your blog. The content will probably just be an extension of what you usually write for your blog: talking about your job, your day, your love life.
3. Click Record, say your piece and save the audio file with a name that identifies it, perhaps the date.
4. Log on to your blog and review the rules for uploading audio files.
5. Locate your audio file and upload it to your blog. Now everyone can hear you voice your words on your blog instead of reading them!"
See the site here.