Problem unmuting sound after muting in LM XFCE 13 Maya

[mmutoo]

Hi all.
First of all, I must say that there are similar topics in the forum about this problem. But non of them provides a good answer to it.
I am using LM XFCE 13 Maya on my laptop. The laptop has a mute/unmute key, and I want to use that for muting/unmuting my sound. I can mute the sound with no problem at all, however, to unmute the sound I need to do that from other ways like clicking on the sound indicator icon in the systray. I have found that people solved the problem with removing the pulseaudio package and the relevant packages, but that also removes the sound indicator package which I don't want to be removed. Is there a way I can take back my unmuting key?

Thanks to all.