audioOS 9.9.15.4 (build 19L6440) is an official Apple over-the-air update for the HomePod (Unknown Model), released on 2022-03-14T17:12:27Z. The update package is 1.92 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 53c90a811f36979e808a70f83deb61f35c4ef2a5.zip.