  We study a gas flow in the Laval nozzle, which is a convergent-divergent tube
that has a sonic point in its throat. We show how to obtain the appropriate
form of the tube, so that the acoustic perturbations of the gas flow in it
satisfy any given wavelike equation. With the help of the proposed method we
find the Laval nozzle, which is an acoustic analogue of the massive scalar
field in the background of the Schwarzschild black hole. This gives us a
possibility to observe in a laboratory the quasinormal ringing of the massive
scalar field, which, for special set of the parameters, can have infinitely
long-living oscillations in its spectrum.
