Green’s Dictionary of Slang

tin-eared adj.

[tin ear n. (3)]

foolish.

[US]B. Appel Power-House 12: You tin-eared stooges!
[US]Kerouac letter 5 Oct. in Charters II (1999) 371: Now I’m a tin-eared Canuck instead of a golden-tongued Jew, says Newsweek.