In 1969, experimental music composer Alvin Lucier recorded his voice, played back the tape and re-recorded, played back that tape and re-recorded, and so on. After enough iterations, the resonant frequencies of the room reinforced themselves to the point of dominating the recorded sound.
This recording from 2021 is Nathan Moore doing the same thing, and with similar results. Iterations 2 - 20 were played through a stereo pair of PreSonus speakers and recorded by a Rode PodMic placed approximately 18" from each speaker.
