An experimental investigation of flow-induced acoustic resonances in an axial flow compressor (conducted at the University College Swansea) is described and discussed. A further experimental investigation of tandem plates in a wind tunnel, as a model of the turbomachinery blade rolls (conducted at CSIRO, Melbourne, Australia) is presented. This is done both in terms of a new phenomenon which has been identified and also in terms of the correlation between the experimental data gathered in the turbomachine and the wind tunnel.