I'm having this same problem now. I'm betting it's IC2 just because I just recently added extra machines and solar panels. This only started happening when I have about 6-12 machines running at once and while I'm a good distance away.
My current setup is 9 macerators, 9 electric furnaces stacked 3 high and next to each other. They are getting power from bat boxes above which get their power from solar panels. Whenever I got to my animal farm or the village nearby the sound just randomly cuts off. I don't know if it's too many sounds running at once or if it's something else.
I'm going to try increase the "soundSourceLimit" but if that doesn't work I'll just disable IC2 sounds for now until this fix.