Note: I checked this question and all of the duplicates listed on it, and none of them seem to address this exact problem.
This is a Windows 7 desktop computer built around an ASUS P5Q Turbo motherboard and a Radeon HD 7800 Series graphics card.
Every so often this computer will emit two rapid beeps through the sound card while Windows is running. I am positive it is going through the sound card, through the "line out" jack, and through my desktop speakers. It is not the internal PC speaker. (For what it's worth, I even tried disabling the "System speaker" device in the "System devices" category of the Windows Device Manager; the beeps still occur.) It is also not a BIOS/POST beep code, as Windows is running normally when it occurs. I've watched the Volume Mixer, and either the source of the beep never appears or it comes and goes so quickly that it can't be seen.
The beeps are rapid. About 1/8 of a second on, 1/8 of a second off, 1/8 on. It doesn't recur very often or very predictably. I am certain it is a beep -- a tone coming from a simple signal generator -- and not a recording of a ding or a bloop or a chime anything to that effect. It is not noise or interference; it is a clear, loud, intent beep.
There are no background programs of any interest running on the system. It tends to beep most reliably when I am copying a large amount of data from disk to the network. The only guess I have is that it's a temperature alarm, but I cannot for the life of me find out where that would be configured, or why it chooses to route its sound through my audio hardware instead of using the PC speaker.
What's making it beep, and what is it trying to get me to do?
