The ear is innocent.
I’m all ears, wants to say: I am attentive. I dedicate all of my time and attention only to you. But it is often used to calm down the other in order to continue with what one was doing (cleaning up, washing the dishes, writing an e-mail).
I cannot hear anything is a way to avoid saying I don’t understand or don’t want to understand.
Everyone knows the gesture of politicians tipping at their ears to indicate that something is not working with the simultaneous translation. How often do they do this, when they don’t understand what they hear? How often do they pretend to not understand acoustically because they don’t want to understand what they hear?
Are you deaf? Is a very tricky insult. It pretends to ask in a polite way: Are you stupid? But in reality says in an unpolite way: You are stupid? Are you deaf? Says: Are you so stupid that I have to assume you are deaf, in order to explain myself how it is possible that you cannot understand something so easily understandable? While pretending to ask: Could you not hear acoustically what I was saying?
And finally I cannot hear you, is another way to say I will not listen to you. I will not obey you.
The ear remains innocent.