Hearing a Dial Tone Beep coming out of nowhere on my MacBook Pro

Within the last few weeks I've been hearing a dial tone beep coming out of nowhere through my MacBook Pro (10.4.1). It just cuts in with a single beep -- like as if my own machine is trying to dial out to a modem. If I'm typing, it temporarily freezes up my computer and the keystrokes don't appear until the beep is finished.

It's almost like something is trying to communicate with or cut-in to my computer. I'm worried that this could be some kind of hack. I've had this computer for 5+ years and never experienced this before. I've also never dialed out to a modem with this computer. I'm working at home from my own encrypted wireless network.

Can anyone share any insights on what might be going on here? Thanks.

 

Have you installed or updated any software around that time? There's likely a program doing that -- the question is what. Check the console log after you hear the sound to see if entries correspond to the timing of the noise. That might provide a clue.

I'd also suggesting posting the question in the MacRumors forums -- a lot more Mac users hang out there. Perhaps someone will recognize your issue.

 

It could be some kind of hardware or low-level driver error producing a 'PC speaker' type of beep, if you open a console you can probably get a log of it when it happens next. If your OS hangs until the beep is over it suggests that this is likely.

Some generic troubleshooting things that could help:
Using Disk Utility to verify or repair disks
About Disk Utility's Repair Disk Permissions feature
Intel-based Macs: Resetting the System Management Controller (SMC)