Lol, Aargh, it's the dreaded PC speakers. I think i just went tone-deaf for a few moments. Honestly, i don't why anyone would want the PC versions, oh wait, maybe it's that awesome music and those snazzy graphics.
The best part always was when you were playing PC games in the middle of the night, and you forgot certain game used PC beeper, or you had incorrectly set the game to use it. TEE-TOOOT-TEE-TEE-TOOOT... sure to wake up the whole house, maybe even neighbours. Franctically searching a key to switch off the sounds, or exit the game... or if all else fail, hurry for the power button. The PC beeper seemed awfully loud in many PCs.
Frankly, very few PC games back then were more enjoyable with sounds on, rather than off.
It's very nice nowadays though as even the PC speaker sounds come muffled through the normal sound system, as you play the games in DOSBox. I guess some sound cards also let you somehow channel the PC beeper sounds through them, maybe by connecting some cable from the motherboard to the sound card, I don't remember...
From my point of view, pre-1989 or so, before the PC sound cards, was purely Amiga-era as far as computer gaming goes.