Never had missing time myself but the humming thing is really interesting to me from a research angle. I've read probably a dozen accounts over the years where people mention a low frequency sound right before things go blank, and I always wondered if that's consistent enough to mean something or if its just the brain filling in gaps after the fact.
Does anyone know if there's been any serious attempt to catalog these sounds? Like whether the pitch or duration varies between cases or if it's always roughly the same description. I'm curious whether people who've had multiple experiences report the same sound each time too.
What did yours sound like exactly - more of a mechanical hum or something you felt as much as heard?