ear! ear!

cauliflower ear — an ear thickened or deformed as a result of repeated blows, typically in boxing

tin ear —  inability to hear differences in musical sounds and subtlety in verbal expression

shut your ears — to refuse to listen to something

turn a deaf ear — to ignore or refuse to listen to someone or something

not believe your ears — to be very surprised at something you hear

smile from ear to ear — smile widely because you are very pleased

go in one ear and out the other — to be forgotten quickly

make a silk purse out of a sow’s ear — make something good from what seems like useless material

pig’s ear — Cockney rhyming slang for beer

in a pig’s ear! —  an expression of disbelief

make a pig’s ear of — make a mess or a muddle

Isn’t it amazing how many idioms have been built around the ear? There are more to come, but I’ve lumped all these together because they don’t have interesting histories or even any controversy about their sources.