How do you say the experssion, "in one ear, out the other" in Cajun French?

"Vera Gabielle" has provided what I recognize as a literal translation of the words in your question, but I thought there was an idiomatic phrase for this.

For example "bête noir" literally means "black beast" but it is idiom for "thorn in the side of."

Unfortunately I cannot recall the phrase I think exists and I am not sure there even is one.

I am hoping that "Vera Gabielle" will revisit this and clarify the literal aspect of the translation offered and correct me.

What first involves my brain is meals... or perhaps voodoo queens... no, that is coz I noticed your monitor title... as we are within the tune segment, I'll say Clifton Chenier, Buckwheat Zydeco and Doug Kershaw.

cela entre par une oreille et sort par l'autre

xxx