Thanks so much for your caring response, strat (if I may shorten that - since that's what Stratocasters are usually called). Your comment made a big difference to me.

Today I wore my earplugs AND a construction type noise-reduction earmuffs on my lengthy commute. I heard a little crap, but no actual conversations or distinctive voices. What a relief. I habitually just use earplugs, but I'll be wearing those earmuffs every day, and my husband will have to get a new pair for himself.