The effects of ultrasound cavitation depend on both the insonification conditions and the liquid characteristics, by means of their influence on the bubble cloud. For this reason, the study of the cavitation bubble field is of interest. The implemented hyperfrequency method allows the monitoring of the bubble volume rate, called void rate a, during the insonification, versus acoustic pressure or dissolved air concentration in water. On the other hand, the oscillating behavior of bubbles found expression in a characteristic acoustic spectrum. The cavitation noise power, defined as the integral of the cavitation acoustic spectrum, permits the estimation of the importance of the dynamic activity of the bubble field. The aim of this paper is to set the relations between the void rate evolution and the cavitation noise power. The evolutions of the cavitation noise power versus the void rate will be examined in two situations, whether the void rate evolution is due to the acoustic pressure variation or to a change of the dissolved air content in water. A link between the cavitation noise power and the increased speed of the void rate will be set.