talk to a brick wall

be like talking to a brick wall

To be completely ignored or disregarded by someone; to be as useless or ineffectual as talking to an inanimate object. Talking to you when the TV is on is like talking to a brick wall. Hello, can you hear me? Trying to give my grandfather advice is like talking to a brick wall—he's just so set in his ways!
See also: brick, like, talk, wall
Farlex Dictionary of Idioms.

talk to a brick ˈwall

(informal) used when somebody refuses to listen to your advice, ideas, explanations, etc: Talking to him is like talking to a brick wall. He just won’t listen.
See also: brick, talk, wall
Farlex Partner Idioms Dictionary
See also:
  • be like talking to a brick wall
  • ears must be burning
  • telephone
  • talk through one's hat, to
  • be talking through (one's) hat
  • be talking through your hat
  • nice
  • eavesdroppers never hear any good of themselves
  • Listeners
  • listeners never hear any good of themselves