Laboratory experiment: Listen & Download Laboratory experiment .mp3 Error! Change your browser, please! ⇓ Download Hammering on construction debris ⚠ Church, crowd noise ⚠ Knocking, blowing into the microphone, ⚠ Tambourine ⚠ Daylight lamp, blink, turn on ⚠ Kick the bike pedals ⚠ Umbrella pulling telescopic tube ⚠ Harvesting machine ⚠ Small crank rotation ⚠ Item thrown on the bed ⚠ Balloon bursts ⚠ Opening, closing the umbrella ⚠ ★★★★★