Drone on
Definition 1 of 1
Pro Tip 1/3Negative Connotation
Indicates annoyance or boredom from the speaker’s perspective. 
I had to leave the room because he just droned on.
Pro Tip 2/3Not Literal
Doesn’t mean actual buzzing sound, but a monotonous speech pattern. 
It felt like she would drone on forever about her vacation.
Pro Tip 3/3Emotionally Charged
Used when the speaker’s patience is tested by the long-winded talk. 
His presentation droned on, testing everyone's patience.