A system used in monitoring one or more operating parameters of a coolant-fluid cooled industrial installation includes one or more an acoustic sensors positioned to receive and sense one or more acoustic signals in an installation coolant-fluid flow. The acoustic sensor assembly operates to emit and sense acoustic signals at frequency ranges above and/or below the background noise frequency ranges which are associated with the normal industrial installation operation. Output data signals representative of sensed acoustic signals are compared to target frequency profiles predetermined as representing an acoustic frequency associated with a predetermined installation operating parameter or event.