  Acoustic emission before the failure of heterogeneous materials is studied as
a function of applied hydrostatic pressure. A formula for the energy release is
suggested, which is valid in the whole diapason of pressures, from zero to the
critical pressure of rupture. This formula is obtained by employing the
extrapolation technique of the self-similar approximation theory. The result is
fitted to experiment in order to demonstrate the correct general behaviour of
the obtained expression for the energy release.
