The next release will no longer use macOS proprietary OpenAL (deprecated and possibly now broken on Tahoe), but an open source alternative. You can try the latest test version from https://jenkins.wildfiregames.com/job/0ad-bundles/93/artifact/

Correct, 26.1

macOS Tahoe?

All unit creation, animal, character, vessel, and building sounds are currently missing in my game, although attack sounds, the flare marker sound, and other effects still play normally. I am using a MacBook Air M1 and have already attempted a full reinstall of 0 A.D., including deleting all related files and even reverting to a previous version, but the issue persists. Despite these steps, no ambient or interaction sounds (such as movement or construction) are restored. No errors pop up either. 

Let me ask to an expert. @Stan` Have you ever seen that format? Another person you can ask is @nifa. Apparently with pluggings in Blender.