This paper presents an analysis of selected acoustic properties of gear pumps. For this purpose, the characteristics of selected types of displacement pumps—gear pumps—are discussed, as well as discrete methods of identification and classification of acoustic signals. The basic assumptions of noise analysis in reverberation chambers are discussed, and an analysis of the distribution of measurement points using decision trees and statistical analysis of measured noise levels was conducted. The object for the conducted research was a gear pump with a undercut tooth profile developed by Wytwórnia Pomp Zębatych Sp. z o.o. in Wrocław. Our own research indicates that the acoustic performance of gear units depends on a number of factors, including, in particular, the technology and quality of manufacture and the geometric parameters of the toothing. The aim of the analyses presented in this paper was to determine which of the microphones has the most important impact on the level of determined measured noise generated in the acoustic chamber. The paper presents an analysis aimed at ranking the importance of eight measurement points in which the microphones are located. To this end, induction trees were developed, and a statistical analysis of the measurement results obtained for selected frequency and sound pressure ranges was prepared. The analysis made it possible to optimize the arrangement of microphones in the chamber without unnecessary analysis of each of the microphones separately.