Here is the ROM mapping for SO:
https://github.com/mamedev/mame/blob/master/src/mame/drivers/model3.cpp#L5246
and
Here is the ROM mapping for SO Final Edition:
https://github.com/mamedev/mame/blob/master/src/mame/drivers/model3.cpp#L5320
in each section if you scroll down to the area called "dsb" those are the ROMs on the Digital Sound Board.
each line here describes the name of the ROM file, the starting position of the ROM file, the size of the ROM file and then a CRC of the ROM file.
The CRC is a mathematical equation that can be run against the data in the file, it's used to check that the data is what you expect it to be.
For instance if I am sending you a file and I want to make sure it transfers ok I'll run a CRC algorithm against it, then send you the file and then you can run the same CRC algorithm and if you get the same number I did, then it means that the file is exactly the same. the SHA1 is a similar kind of check, just with a different algorithm.
MAME records the CRC for every ROM file so that when you load a game in MAME it can check that the file is correct. These CRCs are also an easy way to determine if 2 files used in different versions of the game are the same or different.
A lot of times when you have ROMs from Japan vs ROMs from USA you can check the CRCs for the two games and discover which ROMs are different and which ROMs are the same.
The CRCs are different for every DSB file between SO and SOFE, so that means that the data in those ROMs are different.