audioOS 9.9.16.4 (build 20L497) is an official Apple over-the-air update for the HomePod mini, released on 2023-03-27T17:13:28Z. The update package is 1.2 GB. This is a delta (partial) update that requires 15.5.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: db860422308f2f579bedd99b32f3a59cbf452288.zip.