[deanhills]

What exactly are the symptons? Does this beep happen on boot? When it happens do you have post -> it continues to boot into the OS. Does the beep happen during usage when you are already in the OS and are doing your work, browsing and etc? When did it start to happen? How does the system operate in general? Do you have issues with it?

Is it really a beep? Sometimes hard drives or speaks can emit a similar sound but it doesn't sound exactly like a beep from a mainboard speaker and is not as loud as a mainboard beep. Maybe even the mainboard beep speaker might have an issue and is producing a unnecessary sound. Like you might have experienced speakers popping when shutting down or starting a system. Something similar could be happening here that leads to the beep even if everything is fine.

Have you already done a diagnostics run when it occured? The Optiplex page has so many different beep codes and many of them say to "Run Diagnostics".

It's not a loud beep.  It's been around for probably the last year or so.  It happens while I'm doing my work, when I'm in the OS.  I don't have any issues with the system.  The beep sounds almost like an interference of a kind.  Very brief, not very loud.  Almost like a disturbance.  But very occasionally only - like once a day or maybe even only alternate days.  It's had me curious as to its origins, but since I haven't been having any issues with the computer (other than with Windows updates) I haven't been worried about it.