Are you kidding? On a commercial flight, between the safety briefs, seatbelt warnings, and "turn on/off your devices" there are constant announcements. And the stupid entertainment systems you cannot turn off, or at least that spring to flashing life again after each pointless announcement. I wore my ear defenders on united once, and was woken mid-flight by a steward informing me they were not allowed as i wouldnt be able to hear announcements.