Minecraft wiki entry for Resource_Pack, associated text: Resource packs load additional sounds with the file type of .ogg. Each sound placed in the pack overrides the sounds from packs below, and packs also contain a file called sounds.json which is placed within assets/minecraft. Unlike most other files in resource packs, sounds.json merges sound information from packs below the top pack, rather than each sounds.json file overriding the previous completely.