The results indicate that in case of the composite the amount of crack growth during unloading was higher than t hat of loading. These variations depend on the indentation load and of course on the inhomogeneity of the material. But in the case of zirconia toughened alumina and alumina based wear resistant ceramic, less AE activity was observed during unloading. At higher loads AE activity was more pronounced in these ceramics which was not observed in the case of composite. In all cases, hold time had no effect on AE activity. Also the indentation fracture toughness varied linearly with the square root of crack length. This is indicative of compressive residual stresses being present in t he material which has been confirmed by indentation technique. Indentation fracture toughness testing generated AE signals between 40 to 80 dB in the case of the composite material, which is relatively hard. But in the case of other ceramics, less intensive AE signal was observed.