After a long time finally I've checked the multimedia controls, thanks to
everyone, but for audacious there is no need to install new controls.
  What you can do (in a dell inspiron 8200, but I thik it can work for
other laptops and PCs with multimedia controls) is to open *audacious*, go
to menu clicking in the upper right corner, there click on *Preferences* an
then go to *Plugins* tab, once you are there select the *General* tab and
click on (check) the *Global Hotkey* and *Gnome Shortcuts* options, maybe
you should see preferences in the Global Hotkey plugin.
  It takes some time to work, you should take a look in the preferences for
the plugin repeated times, but finally it works. For other multimedia
software there should be the same options but I haven't taken a look in
others.
   Hope it could be usefull for everyone, hope to see activity again around
here.
          Vladimir