Audio over DisplayPort, but bnot laptop speakers!?

When I plug my M4400 into my TV via DisplayPort->HMDI, the video and audio play fine on the tv.. However the video and audio also continue to play on the laptop. The video is no big deal- I can lower the lid, or point it in a different direction. But the doubling of the audio through the laptop speakers is a serious pain. Unfortunately I can't figure out any way of silencing the laptop speakers without also silencing the sound going out over the display port. I have to e missing something- what's the point of the display port if you can't send video/audio over it exclusively? What am I doing wrong?

 

Control panel -> sound -> select the display port output as the default sound output

You will have to change it back later.

 

Just turn the volume on your notebook to zero. The DP-HDMI will still transport the line signal.

 

For me the volume is linked, so when I lower the volume on the computer the sound coming out over the DP-HDMI goes down too, all the way to zero..

My work around was to stick a headphone plug into the headphone jack on the notebook, so no sound comes out of the notebook speakers, but still goes out over the display port.

 

You could just set the Displayport audio device as the default, and turn off the default notebook speakers/mute them. That works as well.