<div class="htmlview paragraph">Much research has been carried out investigating the generation of noise from hydraulic circuits. This paper attempts to give an appreciation of the main factors influencing this noise generation in a way that is useful to circuit and component designers.</div> <div class="htmlview paragraph">The main body of this paper summarises 11 different techniques for reducing fluid borne noise from gear pumps and discusses the benefits and pitfalls of each method. Test results are given for two different methods that show substantial reductions in fluid borne noise while still maintaining comparable size and performance.</div>