This near-real-time audio stream originates from a seismometer at Eskdalemuir, Scotland (IRIS/IDA station ESK). The low-frequency sounds of the solid Earth have been speeded up by a factor of 1,800× to make them audible. As a result, frequencies have been transposed upward by about 11 octaves. Each successive audio program (separated by a brief pause) compresses the last 168 hours into about 6 minutes (exactly 05:36) of listening time.
The Earthsound Project is hosted here: http://www.earthsound.com/index.html