Until now, the fact that specialists were necessary for performing noise diagnostic measurements as well as for interpreting the results has been the main impediment to a large-scale routine application of noise diagnostics to pressurized water reactors (PWRs). In order to develop noise diagnostics into a process-measuring method that can also be used by the operating crew, a higher degree of automation based on objective measuring and processing procedures is especially needed. At a working nuclear power plant with a PWR, a noise diagnostics system is being tested that largely meets these requirements. Well-known disturbances capable of causing damage to critical plant components are carefully tracked by automated devices, so-called monitors. Such disturbances are, e.g., occurrence of loose parts in the primary circuit, anomalously working coolant pumps, or impacting of control rods. An overall surveillance not dedicated to special processes and therefore with a lower degree of sensitivity is performed by means of pattern recognition methods on a computer.