A sponge cover approach to reducing flow noise of hydrophone

When water flows through the measuring hydrophone and its cable quickly, pressure interference is produced. In this paper, sponge covering the hydrophone is used to isolate the impact of water flowing through the hydrophone and eliminate the burr noise in the signals. Results of the flow tests show that the sponge can effectively filter out the pressure interference caused by water flow, and of little attenuation to the signals of appropriate frequency. So the sponge is kind of a simple and efficient dome, and is able to improve the performance of hydrophone in daily underwater acoustic measurement.