Acoustic survey

a well logging method that measures the time required for sound impulses to travel through a given length of rock to permit estimation of the rock porosity of a given formation and of the type of fluid contained in the rock. This process is also called sonic logging.

A systematic method of gathering information on fish availability and abundance in a water body with the help of sophisticated instruments, such as echo sounders and sonar, that employ ultrasonic sound for the detection of fish. (Commonwealth of Australia, 1997)