audioOS 9.9.15.0 (build 19J346) is an official Apple over-the-air update for the HomePod, released on 2021-09-20T17:12:08Z. The update package is 1.19 GB. This is a delta (partial) update that requires 14.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7475044983493fe73eadc8a367037f9a5b5d0020.zip.