Method and apparatus for determining the sensitivity of an acoustic detector device

An apparatus for determining, in an environment, the magnitude of the smallest physical phenomenon detectable by a sound emission detector device capable of detecting a physical phenomenon that produces a spatially limited sound emission from a volume of 10 cubic centimeters or less, the detector device comprising (i) a transducer array arranged to measure physical parameters related to sound, and (ii) processing means arranged so as to be capable of locating a source of sound emission from signals generated by the transducer array, the apparatus comprising:

• receiving means adapted to receive at least one signal from at least one respective transducer of the transducer array when the array is placed within the environment,
• processing means arranged to add a simulated signal of a predetermined value to the at least one signal from the transducer array to produce a combined signal, the simulated signal corresponding to a computed or recorded signal of a spatially limited sound source, and to process the combined signal and to repeat the receiving and adding steps with a differing predetermined value of the simulated signal until an acoustic threshold value representative of the smallest detectable spatially limited sound source in the environment is determined, and to determine, from the acoustic threshold value and as a function of distance, a quantity representative of the magnitude of the physical phenomenon as a function of distance related to the smallest detectable spatially limited sound source in the environment,
• transmitting means to transmit a signal in real time to a display, the magnitude of the physical phenomenon related to the smallest spatially limited sound source detectable by the detector device within the environment.

A sound emission detector apparatus for detecting, in an environment, the magnitude of a physical phenomenon producing a spatially limited sound emission from a volume of 10 cubic centimeters or less, the apparatus comprising:

• a transducer array having a plurality of transducers arranged to detect sound emissions within the environment and produce signals representative of the detected sound emission,
• a signal receiver that receives signals from at least one of the transducers of the transducer array,
• a processor programmed with instructions for processing the received signals, including producing a combined signal by adding a simulated signal of a predetermined value that corresponds to a computed or recorded spatially limited acoustic source, processing the combined signal and repeating the steps of producing and processing a combined signal with a differing predetermined value of the simulated signal until the smallest detectable spatially limited acoustic source in the environment is determined, and detect at least one spatially limited acoustic source and determine a value of a parameter representative of the sound emission of the spatially limited detected acoustic source and convert the value of the parameter representative of the sound emission of the detected acoustic source into a quantity representative of a magnitude of the physical phenomenon as a function of distance,
• a display for displaying in real time at least the quantity representative of the magnitude of the physical phenomenon.