Yes, continuous sound is heard in both left and right earphones. In both 3 conductor or 4 conductor jacks an improperly inserted plug results in the right channel sound heard in the left earphone and dead silence in the right earphone. Sound is always heard from the phones and speakers simultaneously. The jacks are either not switched jacks or Hp has wired then in a way to bypass the switches. The problem is clearly a software problem needing a key press or mouse click to correct it.Right clicking reveals a different menu from yours. Clicking on Sounds just shows a single source labelled speaker/headphone. Still can not mute the speakers when plugging in the headphones.