A childhood belief about aeroplanes

When I was a kid, the room of our house that I most seldom went in was my sister's bedroom. It was in a wing of the house that came closest to the house next door. So I've finally decided that echoes between our house and the one next door might explain the different sounds I heard occasionally when I did go in her room, like when my sister was away and I was preparing the room for other guests or something like that. Anyhow, on some occasions when I WAS in that least familiar room of the house, I would hear airplanes flying over. Not surprising, except that they seemed to make an eerily different sound from airplanes ad I'd ever heard them from anywhere else, including other rooms of the house. For quite some time that sound had me convinced that those were some strange and different kind of airplanes, whose flight routes took them over that corner of our house, but never over any other part of our house, and so I never heard them from elsewhere in the house. In trying to picture what kind of airplanes those strange and different ones might be, I for some reason pictured airplanes that could fly, even though they had no wings.