Green’s Dictionary of Slang

to cut off; to ignore.

1947		B. Schulberg Harder They Fall (1971) 55: I dialled out on you [...] because I don’t hafta hear all that crap about the village and the wine barrels.
2015		‘Elvis Costello’ Unfaithful Music 325: I sort of dialed him out once I noticed that he wore pads under his shiny Italian suit to protect his skinny kneecaps .