Remember that hoary cliche enacted by all stadium and arena-playing rock bands everywhere: "I can't hear you!", at which point the audience is supposed to drown out an electrically-powered PA system with a spectacular off-tune rendition of the chorus?
Turns out it may not be an act. He really may not be able to hear you, thanks to loud headphones.
My (g-gge-gen-) generation was probably the first one to plug one of them into over our ears. A favorite trick was to turn up someone's volume wheel all the way to MAX before they put on the headphones. It would be doubly funny if the cassette in the player was something like Van Halen's first album (where do you think Robert Zemeckis got that joke from in Back to the Future?) But eventually for most users of the Walkman, the volume wheel would be turned up slowly, notch by notch, as the music got louder and harder and your parents' cries to "do your homework" had to be quickly and efficiently drowned out with soul-rattling guitar. And later, when the Blueness of Our Souls and the Despair in Our Hearts had to be erased with a carefully chosen album like "Dark Side of the Moon", headphones were a damn necessity.
If only deafness turned us into another Beethoven!