Some has translated it into "say something with sarcasm", but it lost the connotation of the literal meaning of this idiom, the strange, unnatural, ugly-sounding and a bit sissy tone.
strange in a frightening and mysterious way
阴阳怪气 describe "an unnatural tone or vibe" (doesn't sound/ feel like male or female) I would translate it as "eerie vibe"
说话阴阳怪气 could be translated as "talk with an eerie voice"
这人阴阳怪气 could be translated as "this man projects an eerie vibe"