The peak frequency of thermal noise at room temperature is far higher than 5 GHz, it's actually closer to 30 THz. I'm not exactly sure about the biology here and whether Brownian motion of air molecules excites the hair cells in your cochlea. I'm guessing that it does, but even so, the range of frequencies you can hear (20-20,000 Hz) carries only a very, very tiny fraction of the thermal energy. Someone should do the calculations; my guess is that it's far below the detection threshold.
Another thing to keep in mind is that at equilibrium, you have thermal excitation everywhere. You might as well ask why you don't hear or see or smell the thermal excitation in your own brain.
Another thing to keep in mind is that at equilibrium, you have thermal excitation everywhere. You might as well ask why you don't hear or see or smell the thermal excitation in your own brain.
I think you are suggesting something like: if I was detecting thermal vibration by the vibration of a membrane due to thermally induced air pressure I wouldn't because the temperature is the same in the air on both sides of the membrane and therefore the thermal air pressure on each side of the membrane is the same and so fails to move the membrane. If this is wha...
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.