@cachondo Those sound schemes came from Microsoft Plus! For Windows 95, though 98 and its respective Plus pack added a lot more.

@cachondo The first version of Windows to really lean into Theming including sound schemes was 95, specifically with the Microsoft Plus! pack which was sold separately, though the base installation did include a few sound schemes on its own like Utopia, Musika, Jungle and Robots. Windows 98 had its own version of plus, which included a unique set of themes different from the 95 ones, but the base installation also included the sound schemes I listed above.

@pitermach I think I was still using a hardware speech synthesizer with 95. I don't actually recall having speakers on my desktop, and of course the PC speaker did its beeps without them anyway. Amazing to think that the entire audio side of things was just missing in my experience.