The investigation on measuring the coefficient of sound absorption at 20–60 kHz in turbid seawater

The seawater, which contains suspended fine clay particles, is called turbid seawater. The research on sound absorption caused by suspended particles in turbid seawater has little been done. A reverberation time technique has been developed to measure the coefficient of sound absorption at 20~60 kHz in turbid seawater. In the test volumes employed, the effect is small. It is therefore measured by taking the difference in reverberation times of a volume of water with and without fine clay particles. Results demonstrate that if the concentration of fine clay particles in turbid seawater is below 110 mg/L, the fine clay particles don´t cause additional sound absorption. However, if the concentration of fine clay particles in turbid seawater is above 140 mg/L, the coefficient of sound absorption in turbid seawater is as twice at least as that in clear seawater. The effect of temperature on sound absorption in turbid seawater has also been investigated.