I feel there is a problem with communication between us. There are no speakers, no external speakers. There are no speakers connected to the PC. Only the monitor in question. The monitor has built in speakers. The monitor has a headphone jack too. As soon as I plug in the heeadphones to the monitor's headphone jack, the monitor's speakers mute and sound comes only out of the headphones. There is no option to go back to the speakers. The only way to do that is by removing the headphones from the monitor. I hope I am more clear this time. Anyway, I just received an email from BenQ (I asked them about this) and they replied with what I was afraid of. It is not possible to both have the headphones plugged in, and be able to choose where the sound comes out of, speakers or headphones.