| Abstrakt: |
Airborne sonic pressures in an open or sealed housing enclosing an aquarium were measured in the air and in the water under near- and farfield conditions. Effective impedance differences were 9.1 dB with the housing open and 4.5 dB with the housing sealed in the nearfield, and 6.5 dB in the open condition and 7.1 dB in the closed condition in the farfield. Both conditions indicated an effective impedance difference considerably less than the 35.5 dB impedance difference between air and the open ocean. Prevalent use of sonic fields in small aquariums thus requires detailed calibration of sonic fields in tanks where the air-water interface is traversed. Because of the 30 dB loss from disruption of the ossicular chain, the ear, in spite of anatomical likeness, is not similar to a closed speaker (eardrum) system over a water-filled tank (cochlea). [ABSTRACT FROM AUTHOR] |
