Audio - Sound Effects Never Seem Loud Enough

No. I'm sorry you've got this problem. The worst thing, audibly, I've experienced is the Karaoke machine likes to cut out from time to time. Sometimes you get the song started and you can hear the voice and the background music. Then sometimes just the voice. Other times nothing at all. Very weird when your Sim is giving a concert. Or, the song IE the animations of the Sim singing on long past the circle being filled yet no sound. But, snow almost always sounds like a blizzard. Most snowfall I've experienced you may not realize it's snowed until you look outside.

Sounds get louder if the camera is near their source and they get faint as you move the camera away. So, if you like to see your sims from up above, the sounds are probably very faint. I, however, only started hearing the ambient sounds after I completely muted the background music.

It’s the same for me. I have to turn my speakers right up if I want to hear the sound in TS4 and I don’t have this issue with previous versions.