Abstract: The present invention relates to a method and associated apparatus for the detection and identification of a sound event comprising collecting audio data from an acoustic sensor; processing the collected audio data to determine periodicity of the sound, processing the collected audio data to isolate transient and/or non-linear sounds and processing the collected audio data to identify frequency modulated pulses, in parallel to produce three output data sets; and combining and comparing the output data sets to categorise the sound event as being mechanical, biological or environmental. The method is particularly useful for detecting and analysing sound events in real time or near real-time and, in particular, for sonar applications as well as ground (including seismic) monitoring or for monitoring sound events in air (e.g. noise pollution).