。
She heard her name being called in the crowd.
Literal
She [topic-は] crowd [possessive-の] inside [in-で] self [possessive-の] name [subject-が] being-called [nominalizer-の] [object-を] heard.
This sentence nests a passive clause inside a perception construction. The inner clause 名前が呼ばれる (passive of 呼ぶ, 'name is called') is nominalized with の, and the whole phrase becomes the object of 聞いた ('heard'). The pattern ~のを聞く captures direct sensory experience — she heard it happening in real time, not that she was told about it afterward. This perception verb + の construction is common with 見る, 聞く, and 感じる.