I have it too to some degree, I think it was worse when I was a child, I remember noticing it profoundly if I were to sit in my mother's Chrysler (the first realy good car she owned -with very strong door seals) with the ignition off. I've had other oddments manifest themselves as well, sometimes hearing in one ear will go for a few moments and come right back, and once in a disturbing episode over a decade ago (I remember distinctly because my father still had his Marantz speakers) everything took on the aspect of an echo chamber, but this was gone by morning and never manifested itself. I used to get ear infections frequetly at a child which certainly explains it. I can only hear it under very perfect conditions -the sealed car, etc. As I am never in such conditions -even the tiny whir of my computer's fans drowns it out, and if I am away it is usually in a hotel with an air conditioner, the last time I remember it distinctly was durring a large blackout several years ago, everything shut off for miles around. I also have excellent hearing for high frequencies, I can hear the 10KhZ squeel form a television picture tube and those stupid electronic pest repellent things. The shrieking of children is painful to me, yet another reason why I hate them.
