The influence of electron spin resonance on generation-recombination noise is studied. In nin-photoconductors made from amorphous hydrogenated silicon (a-Si : H), a resonant decrease of the noise power density is observed. Both the sign of the noise-detected magnetic resonance (NDMR) signal as well as the frequency dependence of the signal amplitude can be described by a resonant reduction of the characteristic generation-recombination time constant. The g-factor observed identifies hopping in the valence band as the dominant spin-dependent transport process leading to electronic noise in this material.