audioOS 9.9.18.4 (build 22L255) is an official Apple over-the-air update for the HomePod (2nd generation), released on 2025-03-31T17:29:48Z. The update package is 1.28 GB. This is a delta (partial) update that requires 17.0 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 9040aaab0b57488a55d0d9f123316b8af5db04b08b095147a51aa2bb926e772b.aea.