Recording setup: I placed the balloon in the middle of the floor and placed the TASCAM recording device approximately six inches away and balancing on the tripod three inches above the ground.
About this recording: This balloon pop took place in the echoey area right by the entrance to the Rose Hills Theatre in the Pomona SCC. The ceiling is vaulted and the entire surrounding structure is made of stone, but open entrances on three sides allow outside sounds in (in other words, it is not closed-off.) There is also a set of stairs by the third entrance, which could affect the sound.
30 dB decay: .274 seconds
50 dB decay: 1.7 seconds
60 dB decay: 2.76
decay to background level: 1.79, since there was background noise before
The spectrogram indicates a space that does not enable for an even decay of sound. While the balloon sound indeed does decay at a steady rate, the echoey nature of the location shows that it picks up on barely-audible sounds long after the initial sound has passed. There is a steady level of general background noise on the spectrogram (a gray haze) that overlays the more prominent, audible background noises.