audioOS 9.9.18.5 (build 22L572) is an official Apple over-the-air update for the HomePod (2nd generation), released on 2025-05-12T17:13:46Z. The update package is 816 MB. This is a delta (partial) update that requires 18.3 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: b0fb2ae16758a2a45daa3bf5fe03bd767c123e585a83270837fc01157d20a544.aea.