In a recent experiment employing a number of hydrophone systems deployed at various positions in the Northeast Pacific Ocean, several operational periods were dedicated to an ambient sea‐noise study. Signals received at hydrophones distributed at various depths throughout the water column were analyzed to characterize the noise field at each site. The results obtained revealed a noise‐level dependence on frequency, hydrophone depth, and sound velocity profile. The general features of the noise field could be interpreted in terms of distant shipping and local wind effects, the two major directional noise sources believed to be dominant in the deep ocean. This paper discusses some specific features of the noise field and examines the implication of these to the anomalously high attenuations reported so often at frequencies below 100 Hz.Subject Classification: [43]30.20, [43]30.70.