I also have the sound issue. I played without AM after I got IP and didn't have the sound issue. When I put in AM, I didn't have it for a few sim hours. I think it started when my sim took one of those taxi boats. And it's exactly like that "picking the neddle up off a record" like SJActress said - only playable for me if I disable the game sound completely.

Donated $15, it's all I can spare this month