Experimental tests of selected damping and sound-absorbing materials to determine their suitability for sound attenuation of hydroacoustic measuring tank

The article contains a description and results of the measurements necessary to select the optimal material for damping two hydroacoustic measuring tanks according to simple suitability criteria, i.e. obtaining minimal sound reflections from the water surface, walls and bottom in these pools by covering the surfaces with sound-dispersing materials or acoustic absorbers. One will be larger (15x10x10 m) for measurements in the range of possibly low ultrasound frequencies and the other smaller (4x3x3 m). The frequency characteristics of these materials, but also the price, ease of assembly and cleaning, and ageing, are decisive for their usefulness. Attractive (according to these criteria) patches of ‘synthetic grass’ and plates made of various plastics were selected for the measurements. The obtained results were compared with the measurement results of the long-used curtains made of dissipative brushes for dampening the measuring tank of the Department of Sonar Systems (DSS) and with those presented by a specialized manufacturer of commercial absorption plates.