Standard definitions for sound levels in the ocean

Measurements and calculations in underwater and bioacoustics should use as the primary reference the International System of Units commonly referred to as SI metric. Relative levels are important quantities provided the reference is specified and the modifier to the term level is consistent with the reference. In particular one needs to distinguish between pressure, power and energy references. It is recommended that when relative levels are used that the metric units are included in parenthesis. The purpose of this convention is clarity