This near-real-time audio stream originates from a seismometer at Cambridge, MA, USA (Raspberry Shake station R199D). The low-frequency sounds of the solid Earth have been sped up by a factor of 100× to make them audible. As a result, frequencies have been transposed upward about 7 octaves. Each successive audio program (separated by a brief pause) compresses the last 12 hours into about 7 minutes (exactly 07:12) of listening time.
This sensor responds to much higher frequencies than most of the others featured in the Earthsound Project. Most of the signals you hear are of human origin: commuter trains (the swoosh that occurs twice per hour during the day), vehicle traffic on a nearby street, as well as chirps and hums from air conditioners and heat pumps on the roof of the building and in the neighborhood. Some of the sounds are of mysterious orgin. Although the city is a noisy place, occasionally the rumble of a distant earthquake will break through the cacophony.
