Does anyone else hear the Choo Choo?

This is Swamp Rat in Shreveport Louisiana. I just dug my CB base station out after many years of being in storage. To my dismay...it seems I have the entire 40 channel band all to myself. And there is a strange thing happening here locally (which I have verified through a Ham operator friend of mine). I wanted to see if it was confined to us locally or if other CBers nationally are getting it too. The disturbance can best be described as sounding like an old-time steam locomotive going down the tracks at a good rate of speed. Its a choo choo choo choo choo chopping sound...and i can get it simultaneously on 6 to 8 different channels within the 40 channel band. What makes matters worse is that this anomaly seems to move!! If I am on channel 20 and the S-meter is flat...the choo choo will start like its a long way off...then it builds until i'm getting a "9" on the meter! Then it slowly fades away like the the train has past and is disappearing into the distance. But if i flip up to 21 or down to 19...THERE IT IS!!! I thought at first it was my location because i recently moved and there is a tall tower a quarter mile or so from me. But my Ham friend 15 miles away tried to hear me one night on 37 LSB and also got the "Choo Choo" noise on his radio. We are wondering if this is a localized anomaly or if others across America are getting it too. And if so...does anyone know what is causing it? I dont get on the net much...so any response to my email would be appreciated. [email protected] Thanks much in advance for your time! Have a safe and pleasant day. "3's" and "8s" to all...