How do I automatically connect to speakers when tv is turned off?

[Shoelace22]

I have a new pc that my brother built and I usually have a monitor and tv connected through two hdmi's. I can't have it on "duplicate these displays" so I use "extend these displays". I've been trying to get my speakers to play sound automatically when my tv gets turned off so I can hear it even if I just want to use my monitor. Please help me.

 

[ihog]

If it's possible, it's not easy: http://superuser.com/questions/468847/how-can-i-automatically-switch-audio-to-my-speakers-when-my-tv-as-2nd-monitor-is