audioOS 9.9.16.4 (build 20L497) is an official Apple over-the-air update for the HomePod (2nd generation), released on 2023-03-27T17:13:30Z. The update package is 563.65 MB. This is a delta (partial) update that requires 16.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f09a3420a876ac16140a0ccd95da5d6c7432171b.zip.