These two sound-tracks are part of a narrative being attributed to Xini. Xini is a fictitious character. An earlier chronicle of his adventures can be accessed here. these sound recordings are from the time when Xini was eleven years old.
Xini jr. has been going about performing his disasters and accidents. The mood around him is fragile. He has been called to offer an answer; eleven-year-old, there-but-not-there, he stood silent. He says that things around him make sounds. The sounds are subsonic so they can't be heard, but these sounds make him do wrong. People in the room are expectedly apprehensive and he is asked to offer a proof.
He calls a medical equipment manufacturing company and ask them to customize an electronic stethoscope for him. The customization requires them to change the filters and the microphones so that the stethoscope can hear (and record) subsonic frequencies. It becomes a subsonic stethoscope. These are the first few sounds he records with it and in a few days offers as a proof.