We have studied the influence of intergranular magnetic coupling on switching characteristics in Co and CoPtCr thin films. The strength of the intergranular interactions was varied by changing the sputtering pressure and film or underlayer thickness. For each sample we have measured the deviation δM from the behavior expected for noninteracting single-domain particles and correlated the results to the magnetic layer and under layer thickness and to the microstructure of the recording film. We show a correlation between δM and the strength of magnetic coupling. Where similar magnetic parameters allow a comparison, we find a correlation between media noise and the trend in δM.