Many times I've seen people ask about replacing voices, sound effects, and music in 90s games. Stargate in particular comes to mind with its obsession with hurling projectiles at certain geometrically shaped structures. These games, in most if not all instances, rely on PCM or ADPCM encoded audio for sound effects and voices. Music, only on the later Stern titles with certain exceptions like Data East's Guns N' Roses. PCM data is basically a WAV file with phone line quality fidelity, so it was only suitable for speech and really clear sound effects.
The Stern SAM and Spike systems are really easy with Pinball Browser as they use much more powerful hardware. But older games? It sounds simple, but this video explains why something simple on the surface can be very difficult to actually achieve in practice. These pins share many similarities with PC CD-ROM games of the era, in terms of hardware and software limitations. Should be an interesting watch for anyone inclined.