Using version 1.4 of the N64 Sound Tool (released Nov 19 2020), I was able to export Luigi and Wario's "Oh my god!" audio from Japanese version of Mario Party 1 in the known game "Mario Party (J) sfx" as WAV files.
I am interested in importing those into the US versions of Mario Party 1 and 2.
Unfortunately in the N64 Sound Tool, unlike when loading the known game "Mario Party (J)", there does not seem to be an option in this program to import my own audio.
Screenshot shows the US version of Mario Party 1. I have selected Wario's "Doh I missed" audio but am unable to import the "Oh my god" audio.
Additionally, I exported all of the "Mario Party 2 (U)" sound banks and listened to each sound but could not find any of the voice sound effects. They also were not present in "Mario Party 2 (U) sfx".
I downloaded HxD and am willing to manually edit the ROMs if I can.
I wasn't sure how to use a hex editor to change a sound file, though, since this isn't something as simple as editing the value of an RPG stat or something.
I understand that there likely isn't a simple solution to this problem, but if anyone is able to point me in the right direction I would be happy to put in the time to get this working.