My wife says I mumble a lot, enough that it annoys her. I think I'm just soft-spoken.
One night I was sitting on the couch when I called into the kitchen to one of our kids. My wife said, “He can't hear you because you're not speaking loud enough!”
A few minutes later my wife told me about a dream she'd had the night before. She said, “I dreamed you were talking to me but I couldn't understand you because you weren't speaking loud enough. I kept getting closer so that I could hear you better, but you kept speaking quieter. I finally got right up next to you and I still couldn't understand you because then you were whispering.” She then said that my mumbling from a moment before reminded her of that dream and that made her really mad at me. I couldn't help but laugh at that. For a few minutes.