。
She pretended she couldn't hear what he was saying.
Literal
She [topic-は] his [genitive-の] saying thing [subject-が] not-audible pretense [object-を] did.
Notable here for the kanji writing 言う事 rather than the more common kana 言うこと. Both 事 and こと are read こと in this use; the kanji writing is slightly more formal/written, the kana more conversational. Both reach the same meaning — 'the thing said, what (he) said.' Combined with ふりをする, this is the standard 'pretend not to hear what someone is saying' construction.