A passive electro-mechanical device that reduces phase noise in oscillators, thereby improving their frequency precision. The noise reduction device can consist of a pair of coupled nonlinear resonators that are driven parametrically-by modulating their natural frequency in time, through the output signal of a conventional oscillator at a frequency close to the sum of the linear mode frequencies. Above the threshold for parametric response, the coupled resonators can exhibit oscillation at an inherent frequency. The novel possibility for noise elimination is realized by tuning the system to operating points for which this periodic signal is immune to frequency noise in the drive signal, providing a way to clean the phase noise of the driving oscillator.