Ocean surface motions due to wind, sea state and swell patterns are the dominant physical mechanisms for
natural sound in the ocean. Noise is primarily associated with wind acting on the surface, causing wave
activity. In the absence of anthropogenic and biological sound, ambient noise is wind dependent over an
extremely broad frequency band from below 1 Hz to at least 100 kHz. At frequencies below 10 Hz,
interactions of surface gravity waves are the dominant mechanisms for sound generation. Across the
remainder of the band from 10 Hz – 100 kHz, oscillating bubbles in the water column are the primary noise
source, both as individual bubbles and as bubble clouds