Sources of anthropogenic noise are

Sources of anthropogenic noise are becoming both more pervasive and more powerful, increasing both
oceanic background sound levels and peak intensity levels. Ambient noise in the ocean has increased over
the past 50 years at both low frequencies (less than 1000 Hz) and mid-frequencies (1-20 KHz).
Contributors to anthropogenic ambient noise are commercial shipping, defense-related activities,
hydrocarbon exploration and development, research activities, and recreational activities.