Equivalent Sound Pressure Levels of Different Pressure-Gradient Hydrophones at Low Frequencies due to Turbulent Flow

Assuming turbulent pressure fluctuations near a hydrophone to be a substantial contributor to the acoustic low frequencies, the low-frequency response of a pressure-gradient hydrophone with different shapes and sizes is studied. It is demonstrated that the predicted equivalent sould pressure level at low frequencies can be reduced by changing the shape and/or size of the hydrophone. The result of the study shows that a pressure-gradient hydrophone with spherical shape exhibits 4–10 dB reduction in the equivalent sound pressure level as compared with a cylindrical shape at a frequency of 10 Hz.