Hi

I have this problem: When I am in the cockpit in the high altitude the voice of ATC (In Radar Contact) is very weak and I must loud the speaker volume to hear the instructions from ATC correctly and In this way the engine sound will be louder! Is there any way that I could louder the voices in the Radar Contact?

Yes, go into the sound settings and lower the volume of the other sliders until you can comfortably hear the RC voice.

Also if you have windows 7, you can right click on the taskbar sound icon, open volume mixer and increase or decrease each process's sound volume