Sine wave (975Hz): Listen & Download Sine wave (975Hz) .mp3 Error! Change your browser, please! ⇓ Download Lock gate open ⚠ Sand bag ⚠ Noise ⚠ Crashing in the fall ⚠ Escalator ⚠ Bagging in the bag ⚠ Unscrewing and twisting the lid of the ⚠ Tinder duster surface ⚠ Kick the bike pedals ⚠ The subject falls on the wooden floor. ⚠ Small crank rotation ⚠ Harvesting machine ⚠ ★★★★★