Detection of acoustic events

A method for detecting an acoustic event of interest within a three-dimensional volume of three-dimensional space comprising a plurality of sub-spaces, the method comprising:

• a) obtaining acoustic signal data arising from acoustic events generated within the volume of three-dimensional space, by way of a plurality of sensors respectively positioned at known locations around and exterior to the three-dimensional space, wherein the acoustic signal data obtained by way of the sensors is tied to a common time reference,
• b) identifying one or more candidate impulses from the acoustic signal data obtained from the sensors,
• c) defining for each identified candidate impulse of the one or more candidate impulses at least a time stamp within the common time reference and a sensor coordinate on the basis of a sensor of the sensors which obtained the acoustic signal identified as the candidate impulse,
• d) determining, for each candidate impulse, a signal source time in each spatial sub-space of the plurality of sub-spaces within the three-dimensional space, in order to generate a representation of an origin of the one or more candidate impulses in positions in the three-dimensional space and time,
• e) determining, from the generated representation, at least one indication quantity representing a likelihood of an acoustic event of interest taking place in the positions in the three-dimensional space and time,
• f) comparing the at least one indication quantity to a predetermined threshold defined for the indication quantity in question, and
• g) generating an indication that an acoustic event of interest is detected when the at least one indication quantity meets the predetermined threshold defined for the indication quantity in question in at least one sub-space within the three-dimensional space.