I have been looking in the files of this 90s Mac game MacSki, made by D. Cook. Using Infinite Mac emulator, I've been able to open it and make it work quite well (some keyboard issue, well).
We obtain those files :
Among the files, one can find a "MacSki Sounds" file, which seems to contain all… sounds from the game. Was there some specific format for these files at the time or is it a custom format? And subsequently, is there a way to convert it? I can open the file and read this at its beginning (choosing Mac Roman encoding):
v1.5?MacSki Sounds v1.5, Copyright © 1990-1994 by Storm Impact, Inc.
This support document contains all of the sounds for the MacSki application.
Place this in the exact same folder as the MacSki application.
The file is available here: file.io/sgrt6iECvLo1 but can easily be downloaded with Infinite Mac the way I explained.
Edit1:
Result when opened with ResEdit. It is correctly understood as a sound file:
The hex datas look like this: