Occupancy status detection for a vehicle

The occupancy status of a vehicle 100 is determined by receiving audio data 201-1..r from distributed microphones 320-1..r, generating a frequency distribution spectrogram for each audio data over a time window (eg. p FFT'd sliding windows), inputting these spectra into a classification model (eg. an artificial neural network comprising a head sub-network for each location with weighted connection nodes) to classify an occupancy status at each discrete location i=1..N in the vehicle (eg. seats, trunk, footwells) as one of a predetermined set of occupancy types j=1..M (eg. empty, adult, child, dog, cat) and outputting values Oij indicating a probability of the occupancy of location i being of type j, fur use by the vehicle control system. Visual data for each location Vij may also be input to the classification.