Welcome to both of you!
First of all, Jed's problem doesn't seem related to Largical's problem, so I'm not sure why that response was posted. I have some questions, though.
@Largical: Did you lose audio on your entire computer or just the audio of the game? Sometimes the game just stalls on audio and then suddenly comes back. It's a glitch of some sort. Have you restarted the game since then? If it's within the game, it should come back on. I don't think you have to reinstall just yet. And there haven't been any real reports that HEL is causing crashes or loss of audio.
@Jed8762: What you describe doesn't have anything to do with loss of audio that I can see. I wonder if your problem came because of the difference between digital downloads and downloading from a disk. Also, did you install them in order? It's best to install them in the order that they were released, so that would be: Base game, World Adventures, High End Loft, Ambitions.
Also, I changed the subject of this thread to more accurately describe it. Please be as specific as possible when naming your topics so that people who are browsing the forum have a good idea of what the topic is about.