This near-real-time audio stream originates from a seismometer at Santiago Island, Cape Verde (IRIS/IDA station SACV). The low-frequency sounds of the solid Earth have been sped up by a factor of 1,800× to make them audible. As a result, frequencies have been transposed upward 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.