Sword Art Online Alicization Unpacking

[Kizuna]

I'm very new to unpacking and I thought the extent of it would be as simple as unpacking the files with a tool, until I ran into this games files. I successfully unpacked the data cpk having used YACpkTool, and my interest at the moment is retrieving sound effects, but in their respective folder, they all have no extension and are just files. I've looked into this for the past few days and have been conducting searches for the past 2-3 hours on it but I'm still lost here. Some descriptive help would be very much appreciated. https://imgur.com/a/0kaaz8S