Abstract: A device detects an emission source of a vibration signal against a background of noise, where the vibration signal is produced by a mechanical system and has one or more frequency components. A sensor senses the vibration signal and produces a sensor signal corresponding to the vibration signal. The sensor has a mechanical frequency selection structure for mechanically resonating at desired frequencies and for mechanically attenuating a frequency component of the vibration signal having a frequency outside the desired frequencies. The mechanical frequency selection structure thus produces a mechanically-tuned sensor signal. Electrical frequency selection filters electrically attenuate a frequency component of the mechanically-tuned sensor signal having a frequency outside the desired frequencies. The electrical frequency selection filters thus produce an electrically-tuned sensor signal.