audioOS 9.9.15.5 (build 19L570) is an official Apple over-the-air update for the HomePod, released on 2022-05-16T18:23:44Z. The update package is 1.25 GB. This is a delta (partial) update that requires 13.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 426f7a087be56b11e122b4bac7dfe527502bd198.zip.