This Master thesis had the aim to determine the influence of the amount of spinel in magnesia-spinel bricks on the elastic parameters and the damping at both room temperature and high temperatures. Commercially available and industrially manufactured refractories have been used. These are magnesia brick, three magnesia-spinel bricks with different amount of spinel and a magnesia-spinel brick with an additive. The bricks were tested by the impulse excitation technique (IET) at room temperature and at high temperatures. In the end the elastic parameters and the damping as a function of the amount of spinel were plotted. The results indicate that elastic parameters decrease and damping increases with increasing spinel content.