[ubuntu] separate mic/headphone volume control

view story

http://ubuntuforums.org – I installed Ubunut 12.04 64 bit, and it seems I can not adjust volume separately for headphones and laptop speakers. If I plug my headphones in, I can hear sound through my headphones AND my speakers. I can not turn of the speakers, so I can listen music, in the same room where someone else is watching tv. In system settings - sound I can neither alter this setting as needed. Anyone an idea how to change of what software to install that would make this possible? (Hardware is HOP Pavilion dv7) (Hardware)