0x800 header with the sample rate and (maybe) channels. Then 0x20 file header with the data lenght + data, repeat until the end. No file type or anything else.
Probably easy to make a quickbms script, better suited from the Xentax guys I guess.
"Probably easy to make a quickbms script" Well, I really tried to write one but then I realized this needed complex functions, and I had no idea how to handle them so I just left the script as is.