drone on (about someone or something)
to lecture or narrate in a low-pitched, dull, and boring manner. The dull old professor droned on about Byron—or was it Keats? It was Shelley and, yes, he did drone on.
drone (something) out
to make a loud and low-pitched noise; to say something in a low-pitched and monotonous manner. The announcer droned the winning numbers out. She droned out the winning numbers.