。
She pretended she didn't hear me calling.
Literal
She [topic-は] my voice [object-を] didn't-hear pretense [object-を] did.
The pattern ~ふりをする ('pretend to X / act as if X') is built around ふり ('pretense'), the masu-stem nominalization of 振る ('to swing, gesture'). Here the negative plain form 聞かない modifies ふり attributively — 'a not-hearing pretense' — which is then the object of する. 私の声を聞かない is technically a relative clause modifying ふり. 声 ('voice') here stands in for the act of calling — 'didn't hear my voice' implies 'didn't hear me calling.'