Moving on from hand baggage taken with you to the safety briefing.
Boarding an A320 recently (it happened to be BA but could have been any operator), and being seated directly over the wing, the briefing started together with pushback and engine start. In normal A320 manner, where one engine runs before the other, the familiar "dog barking" noise of the Power Transfer Unit started up, and being just underneath our seats it completely drowned out any of the PA announcement.
Should I really draw the attention of the crew and ask for it to be repeated once both engines are running and the racket has stopped ?