EVALUATION OF AGAR, SOLID MATERIAL WITH A COUSTIC PROPERTIES EQUIVALENT TO WATER

The aim of our work is to determine the acoustic caracteristics of aga r, a material acoustically equivalent to water. The advantage of the u se of agar is that it presents properties very neighbouring to those o f water, and it's a solid material. Such properties make its areas ver y diversified and include medicine domain (echography) where it's used as a phantom. It's also used as an insulator to eliminate echos which may be important with respect to informationel echos. So, it's too ne cessary to know his acoustic behaviour by determining the attenuation coefficient, the speed of sound and the acoustic impedance.