On the rare occasion I indulge ( only if I feel that I might have to ) I plug an earpiece and inline mic. into the thing and tuck the earpiece under my headset into my ear, then tell any caller that I'm flying, can't hear, will call back when I'm down, that usually shuts them up as they can't understand a word, but at least I know that the person I was probably expecting to call did so, and they know that I know and wasn't just ignoring them until such time as I choose to check my 'missed calls' (probably about once a week )
NOTHING ( or very rarely ) is anything that important, and it's only when it might be that I take the phone flying.