A system and method for monitoring for a specified frequency band is disclosed. The technology initially utilizes a micro-electromechanical system (“MEMS”) based acquisition device to monitor an environment. The MEMS device receives a signal from the environment, and generates an input signal comprising an electronic representation of the received environmental signal. This input signal is then conditioned for at least one frequency band. Embodiments of the invention next allow the conditioned signal to be compared to various pre-defined events in order to determine the signal's origin.