Ok, I will say a tip.
Open on an Audio Editor (Sony SoundForge, Goldwave, Audacity, etc.) for example, a Mega Drive/Sega Genesis rom.
Normally with this settings: On SoundForge (to the app import and work with the rom) per example
Sample rate 11025 , Sample tipe 8bit PCM, Format Unsigned, Byte order (none), Format: Mono
You click to open and voilá! Appears the track, you can click and play, with success you will find the audio and maybe some music in it.
But this settings vary from game to game. So, you may try changing from 11025 to 8000, 5500 or even 4000 (sample rate) ... And some games only open with Stereo , or even Signed bit.
To change, you must respect the format you'd imported and the same duration of the clip.
To export, simply go to File/export/ As raw
Finished, exported? Now , rename the extension to .bin (Mega Drive)
Do the checksum fix and play to see if worked... sometimes fail, but we are having success...
Please, if you try Fifa 20 by T.A. Marcos, you will listen my voice in the beginning and several new sounds into the game.
ps: Of course this tip works for other system console roms....