The name was given because the sound slowly decreases in frequency over about 7 minutes. The sound was detected at 15°S115°W / 15°S 115°W / -15; -115Coordinates: 15°S115°W / 15°S 115°W / -15; -115. It was recorded using an autonomous hydrophone array. The sound has been picked up several times each year since 1997. One of the hypotheses on the origin of the sound is moving ice in Antarctica. Sound spectrograms of vibrations caused by friction closely resemble the spectrogram of the Slow Down. This suggests the source of the sound could have been caused by the friction between a large ice sheet moving over land.