I also experience this same problem, but specifically, I noticed it happens every time my game loads into the Parkside Place lot from San Sequoia (Growing Together). If I load the game for the first time, it does this beep as it loads into the lot. And if I travel with my sims, when I return home to this lot, the beep occurs. The first time I noticed it I was streaming my game on Discord to someone, and they noticed it too. Considering I was streaming the game and not the screen, he would not have heard the beep if it came from outside the game. Plus it is entirely consistent for me, each time I load into Parkside Place, where my sims live.
I came here to see if anyone else was noticing it, but it otherwise isn't largely impacting my gameplay. But it almost sounds like a microwave beep. Been playing this save on this lot for about a week now, it happens every time.
I'm on PC as well.
Edit: And I have no mods/CC.
UPDATE: I did some more digging around, and found a thread from 2014 about a similar issue... it seems to be tied to the coffee pot on my lot! I put the coffee pot in my household inventory and when I traveled and returned to my lot, the beep sound went away. Specifically, it was the Stainless Steel Coffee-Pot.
