audioOS 9.9.15.0 (build 19J346) is an official Apple over-the-air update for the HomePod, released on 2021-09-20T17:12:06Z. The update package is 1.29 GB. This is a delta (partial) update that requires 13.4.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a126c426112c623b80d7feeab31068beae8e5d36.zip.