I have a Logitech headphone. When I am talking on the phone via my computer others can hear me, BUT I CANNOT HEAR THEM. I cannot hear music through my headphones either. I have checked to make sure the mute button is turned off both on all the computer volume controls and the actual headphone itself. I have double checked to make sure the volume is all the way up on my headphone and it is. BUT THE FUNNY THING IS that when I go into the Master Control Panel, click and drag up the volume bar to the loudest level I can hear through my headphones, both music and people talking to me via my computer phone system. HOWEVER, the bar falls and will not stay at the loudest level. I have tried plugging my headphones into the back panel USB and in front of my computer. I have even tried unplugging my desktop speakers thinking it was conflicting with the headphones somehow? Maybe someone out there is smarter than the Logitech Tech Support Center and our systems administrator?