jmcgready's dashboard

If your headset is a Plantronics USB headset,
there's a known issue/fix that requires a trip to the Utilities Folder

From Apple Support
http://docs.info.apple.com/article.ht...

Solution
1) Make sure the device is connected to a USB port.

2) Open Audio MIDI Setup, which is in the Utilities folder
within the Applications folder.

3) Make sure the Default Input pop-up menu
(under System Settings) is set to the device.

4) Choose your device from the "Properties For" pop-up menu.

5) In the bottom right area of the window (under Audio Output),
deselect the "Mute" checkbox.

at our store we use a clorox bleach pen (brush end works best)
and a napkin to wipe off the bleach.
Make sure you're in a ventilated area,
or major head rush/headache will happen.