Sound Recording One: Air Vent Pipe

As I started out on my drift I took a stroll through my backyard to see if anything interesting could be heard. At the back of my house I discovered a pipe that lead to some air vent that I believe has something to do with the heater. It was making a low steady hum and I was able to get really close to it. I situated the microphones about one foot above the pipe and recorded. Listen to the sound here.