870 Views 1 Reply Latest reply: Apr 11, 2009 2:32 AM by Dai Bach
Difficult to say based on your description.
If it an 'electronic sound' you could check the Console logs to see if any errors are reported at the time the sound happens. It might be one of your start up programs giving an error.
If it's more of a 'physical sound' it's possibly just the hard drive parking it's heads. I'd do a Verify Disk using Disk Utility to check that the drive's okay.