If it helps, here is what I have observed since yesterday when I first reported my loss of sound. I started playing right after the update, and my Sim just stood there frozen while the game clock kept clicking. People around me were moving, but my Sim wouldn't do anything. The sound was working perfectly fine at this point, and I could hear other Sims talking.
Out of necessity, I used the cheat for Reset Object for my Sim. He started moving and doing stuff again, but I almost immediately noticed that the Sims were no longer talking. I tried to sing and there was no sound to be heard. Very shortly after this, all sound disappeared completely. I quit the game to go back to the menu, but even the loading screen no longer had sound.
I mention all this because today I tried to play again. I say try because the game crashed a couple of times, but I digress. This time, my Sim was working fine right from the get go. I DID NOT have to Reset Object this time, and guess what? I had sound for the whole time! I did a cheat to make my sim happy and didn't lose sound. I didn't press my luck with any other cheats, so I'm not sure if others cause a problem or not. It could have just been a coincidence, but I wanted to make a note of it as its pretty important to be able to use the Reset Object cheat from time to time!
