APPLICATION OF PSYCHOACOUSTICS TO THE NOISE SIGNALS GENERATED BY GEAR PUMPS

External gear pumps are simple and robust components suitable to work at a wide range of pressures and rotational speeds. These features make them widely used on different kinds of machines and vehicles and for different applications. Unfortunately, their main drawback is the noise emission which often affects the overall noise emission of the machines which these components are mounted in. Frequently it happens that even if the overall A-weighted sound power levels are adequate they do not assure the customer's satisfaction for these products in terms of perceived annoyance. In order to support gear pump manufacturers with a methodology able to predict not only the overall noise emissions but also the acoustic quality of these components, a specific research project was launched. This study presents the starting steps of this project aimed at investigating the characteristics of the noise signals generated by gear pumps by complementing the classical energy-based description with psychoacoustic analysis. Noise measurements were carried out on different pumps at the same operating conditions and the noise signals were compared each other in terms of dB levels and main psychoacoustic parameters (loudness, sharpness, roughness, tonality, fluctuation strength) in order to see the relevance of each of them.