Abstract: We consider the problem of parametric sound generation in an acoustic interferometer containing a fluid. We have taken explicitly into account both the influence of the nonlinearly generated second harmonic and the effect of the unavoidable rising of the temperature due to the acoustic wave. Two main new features under these considerations can be observed. On one hand, the fundamental field does not achieve a saturating value when subharmonics fields appear, but still grows with the driving. On the other hand, the subharmonics fields can exist only for a limited range of driving value, due to the dependence of the cavity resonances with the temperature of the medium. The experimental setup was designed and we show here the experimental measurements, which are in good agreement with the predicted values for the mode amplitudes and the parametric threshold.