audioOS 9.9.15.4.1 (build 19L452) is an official Apple over-the-air update for the HomePod, released on 2022-03-31T17:15:59Z. The update package is 1.15 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: e1bab9271cfaf8f2c7f6933001c7ee3a3666f41e.zip.