An ambient background noise made by transforming an image to sound with audacity, and then slowing it down. Useful for underwater scene. The source of this sound is this image: <a href="https://www.ee.columbia.edu/~sfchang/course/dip-S04/sample/Contrast-Enhancement/ipexcontrast_files/ipexcontrast_img_11_01.png" rel="nofollow">https://www.ee.columbia.edu/~sfchang/course/dip-S04/sample/Contrast-Enhancement/ipexcontrast_files/ipexcontrast_img_11_01.png</a>