This might be hard to believe. What you are hearing is a treadmill turned off, so that the resistance of the moving mat against the machinery creates a harmonica-like A4 tone (with a fourth below) when pulled. Originally 20 seconds long, I slowed down the resulting sound 4-fold, added compression, a ring-shifter, and reverb. Beyond this drone tone, the strange vocal modulations heard within this recording are bits of dialogue between my girlfriend and I.
令人毛骨悚然的諧波，ambience.wav
聲道：2
類型：wav
loop、odd、weird、ambience、treadmill、landscape、generated、effect、synth、electronic、sound
環、奇、奇怪的、環境、跑步機、景觀、產生、影響、合成器、電子、聲音
資料來源：freesound ( https://freesound.org )