random beep noise when waking up from sleep

[blaklaybul]

when my computer wakes up from sleep mode, I hear a random beep.
I do not have a new email, and I cannot find anyother reason for it.

Does anyone know what this is?

 

[cptpower]

when you wake from sleep, are you required to type in your password?

I've found that entering in my password incorrectly, once I get it right the second time and the login screen disappears, I get a beep.

 

[Sun Baked]

Hard Drives can make this noise if they run a calibration on spin up.