Patent ID: 8847750

Claim:
An occupancy detection network comprising: one or more motion detection modules configured to be positioned in each of one or more defined areas and each effective to provide an output signal based on detected motion in an associated area; one or more sound detection modules comprising one or more sound detectors and a filtering circuit coupled to receive input signals from the sound detectors and to individually filter signals from the one or more sound detectors that are outside of a predetermined frequency range, an analog to digital signal converter effective to average and sample the filtered sound detector signals, and a memory buffer effective to receive the averaged and sampled sound detector signals and store the signals in at least one buffer stage, the one or more sound detection modules configured to be positioned in each of the defined areas and each of the sound detection modules effective to extract a plurality of sound characteristics from ambient sounds in the associated defined area, identify one or more of the plurality of sound characteristics as being associated with occupancy in the associated defined area, based at least in part on detection of the one or more sound characteristics over time in association with output signals from an associated one or more motion detection modules representative of detected motion in the same defined area, automatically adjust one or more sorting criteria over time in accordance with the identified sound characteristics, classify sound as detected occupancy sound in the associated defined area based on a comparison of the sampled signals stored in the buffer in with either initial predetermined sorting criteria or automatically adjusted sorting criteria, and provide an output signal based on detected occupancy sound in the associated area; each of said motion detection modules and said sound detection modules configured to be assigned an address associated with an area in which they are positioned; and a central lighting controller configured to be functionally linked to each of the motion detection modules and sound detection modules via a common bidirectional data bus, and effective to receive an output signal from a detection module, determine an occupancy state for a defined area associated with the detection module that provided the output signal, confirm the determined occupancy state by generating a query for the status of each detection module having an address associated with the defined area, and control one or more associated lighting devices to be turned on and off in accordance with the determined and confirmed occupancy state.