Ezra was before the house of God, that is the temple building. Just like his prayer that was audible (Ezra 9:1–15), Ezra’s weeping would also have been heard by those around him. Biblical weeping was not silent but loud (see Ezra 3:12; Nehemiah 1:4; Joel 1:12–17).1
1 While Ezra prayed and made confession, weeping and casting himself down before the house of God, a very great assembly of men, women, and children, gathered to him out of Israel, for the people wept bitterly.