I fired up FSX after work, and loaded AI traffic. Sliders at 100%. Mine seems to be working, although I expected alot more traffic with all the sliders maxxed out. I sat at Stewart airstrip for 30 minutes, and only one plane came. I moved to KSEA. I can hear the tower and the planes, as well as the ground channel. I requested "Taxi to North Parking", and everything worked like it should. I don't know why you wouldn't be able to hear "some" sounds, but all the others play. Are you referring to the ATC window as the text box? Of course, that would be open.