Disclosed is a system and method for monitoring wind turbines, generally comprising a microphone for picking up acoustic emissions from a wind turbine and outputting a signal corresponding to the emissions; a filter for splitting the signal into a plurality of signals according to a plurality of frequency bands; and a processor for processing the plurality of signals and generating sound level data corresponding to at least a subset of the frequency bands. The system compares the sound level data with a sound threshold and generates an alarm signal when the sound level data exceeds the sound threshold. Alternatively, the system may include different thresholds corresponding to the different frequency bands, and an alarm can be generated when one or more of the different thresholds are exceeded by the different signals in the different frequency bands.