An influence of low-frequency (LF, 27.2 kHz) ultrasound pulses on cavitation thresholds and intensity of sonoluminescence generated by the high – frequency (HF, 730 kHz) ultrasound field has been investigated. It is shown that such a pulse causes decrease of the cavitation thresholds, and increase of a sonoluminescence intensity (in some cases for more than by 2-3 orders of magnitude). The enhanced sonoluminescence emission is observed both in the case of the simultaneous action of the fields and in the сase of preliminary sonification of the liquid sample by the LF field. The increase in the SL intensity, generated by the HF is observed for long time (up to several hours) after switching off the LF source. This is evidence of the long-time afteraction of the LF ultrasound on the magnitude of SL generated by the HF ultrasound.
