"Thum, Thum, Thum, Thum, Thum"
Craig Bartmer, an NYPD officer who was present at the destruction of World Trade Center Building 7, testifies that he heard a series of explosions, "Thum, thum, thum, thum, thum" preceding the fall of the building. At the same time a TV interview is being conducted down the street, far from the building. The microphone picks up the same series of sharp, percussive sounds, confirming Bartmer's description. NIST artificially ruled out all such testimony by setting up a hypothetical loudness threshold for sounds it considered to be capable of destroying columns in the building. The video goes on to question NIST's computed loudness threshold below which they would not investigate explosions.