This happened to me this week sat waiting in a hospital for my 12 week scan. The person next to me was playing music off their phone so everyone could hear it. I thought it was extremely rude but didn't say anything as I was anxious about my upcoming scan and thought the conversation might take a turn for the worse. I've had this several times recently - particularly on buses. Am I BU to ask them to turn it off, or put headphones on?