Can't hear sound out of Headphones on Headset

[CarLBanks]

http://www.logitech.com/index.cfm/products/details/US/EN,CRID=103,CONTENTID=6337

I recently today stopped hearing sound coming out of the headphones and I looked under sound and audio devices and nothing is muted. I set in Teamspeak to have the sound come of out the headset. I think the volume is up high enough.