Phild, You're right about the humid air/dry air thing, but since air-conditioning is designed to remove humidity from the air this probably wouldn't be pertinent to listening indoors (this time of the year anyway). As to sound "pressure" levels, you've probably got something else going on. Mwalsdor, do you use a subwoofer in your system? If you do, my bet would be that you have your sub turned up too high. Those low frequencies will increase the sound pressure level dramtically, yet still be inaudible. If you have a sub, turn it down to where it still reinforces the low end but doesn't give you a headache! Tony