We report on the measurements of broadband voltage noise generated by the driven vortex matter in and just below the peak-effect regime of a thick amorphous Mo$_{x}$Ge$_{1-x}$ film. We focus on a change in broadband noise as the system undergoes the mode-locking (ML) resonance (ML freezing), which occurs when the ac drive superimposed on the dc drive excites the lattice-oscillation modes collectively. Independent of the field studied, the noise spectrum at low frequencies $f$ is of Lorentzian type, while it is $f$-independent at high $f$ (but well below the ac-drive frequency). We find that the magnitude of noise at high $f$ decreases in the ML resonance.
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