Synonyms

Dear Forum Users,

Below you can find an extract from my essay. I just cannot find the right word for what I call an 'overhearer':

"In most cases the ironic speaker and the target are distinct entities but, as we shall see for example in self-directed irony, in some other instances the ironist and the victim of his criticism are identical. Furthermore, it may well be the case that it is not the hearer who functions as the target of irony; he is in the role of a neutral ‘overhearer’."

I mean:

Husband to wife ironically: "This is a beautiful painting" -- can the wife be called an 'overhearer'? I intentionally ignore the term 'hearer' here.

Thank you.

Pal