Are you talking about the "Submarine_DiveAlarm_INT.wav" file? In "Stock" game, the file is 2 seconds long. It's "mono" (one channel) at 22.05kHz frequency. In Fall of the Rising Sun Ultimate, it is now 17 seconds long, "stereo" (two-channel) at 44.1kHz "CD Quality" frequency - basically the same frequency, just two channels... You don't want the file to be much longer than that, time-wise, figuring that 18 seconds is about the limit... Files often don't play if the frequency of the file doesn't "match" what the computer (Windows) is set to, unless the game's "player" does sample rate conversion on-the-fly for you... If you need an editor to change things, check-out
Audacity. If you've got something like Sony Sound Forge or similar, all the better...