  Superradiant scattering of linear spin $s=0,\pm 1,\pm 2$ fields on Kerr black
hole background is investigated in the time domain by integrating numerically
the homogeneous Teukolsky master equation. The applied numerical setup has
already been used in studying long time evolution and tail behavior of
electromagnetic and metric perturbations on rotating black hole background
[arXiv:1905.09082v3]. To have a clear setup the initial data is chosen to be of
the compact support, while to optimize superradiance the frequency of the
initial data is fine tuned. Our most important finding is that the rate of
superradiance strongly depends on the relative position of the (compact)
support of the initial data and the ergoregion. When they are well-separated
then only a modest -- in case of $s=0$ scalar fields negligible --
superradiance occurs, whereas it can get to be amplified significantly whenever
the support of the initial data and the ergoregion overlap.
