Cavitation noise measurement using three different instrumentation schemes on four pumps having different impellers but the same casing forms the main aspect of this paper. Either a microphone or a hydrophone was used as the noise transducer. The analysis of the signals were done in the frequency domain using an audio frequency analyser, a heterodyne analyser or a real time FFT analyser. The techniques of these measurements are presented. The results are analysed and compared with those of previous investigators.