At about 4am, I was awakened by someone talking in an Asian language over music... coming from my computer. A few minutes later, it occurred again so I went to my computer to look for the source.
Couldn't find anything obvious, but in Windows Task Manager, I found a process called taskmagr.exe using resources, and iexplore.exe running, though Internet Explorer wasn't running (visibly).
If I selected iexplore.exe and stopped the process, the voices and music stopped... only to begin again a few minutes later, with a new instance of iexplore.exe running. I turned the sound off and went back to bed.
In the morning, I Googled the voices and music and found more than one link stating that it was being caused by something called taskmagr.exe (not taskmgr.exe). They suggested finding and deleting that file. I found it in Windows/System32 and deleted it.
Left the sound on yesterday and overnight, and the voices/music have not recurred. Search on this site finds no reference to taskmagr.exe. And my computer SEEMS to be working faster.
I am going to change the file extension and save this file in case someone technically competent wants to see it.