Abstract: A signal processing system comprising coding means operable on an applied input signal for affording a plurality of successive waveform shape descriptors indicative of the applied signal and for comparing successive pairs of corresponding shape descriptors to afford a succession of outputs indicative of the differences thereof and characteristic of the applied signal.

Abstract: A security device and a security system incorporating such a device comprises a portable secure object which includes a unit for storing information, a unit for storing a voice biometric signal or a signal indicative thereof, and an integral microphone. The microphone generates the voice biometric signal during a registration procedure, and subsequently derives a further voice biometric signal for comparison with the generated voice biometric signal for subsequent interrogation purposes.

Abstract: A signal processing arrangement for a band-limited input signal, comprising a plurality N of signal comparators. Each signal comparator is adapted to compare the input signal with a plurality of different exemplar signals and to generate an output indicative of which of the exemplar signals corresponds most closely to the input signal. Each of the exemplar signals is arbitrarily derived independent of any expected input signal. The arrangement provides an N-part output signal which is indicative of the input signal, such that each part of the N-part output signal is derived from the output signal of a respective one of said N signal comparators.

Abstract: A signal processing arrangement for discriminating a time varying band-limited input signal from other signals using time encoded signals. A received input signal is encoded as a time encoded signal symbol stream from which a fixed size matrix is derived. A plurality of archetype matrices corresponding to a plurality of different input signals are stored, each having been generated by encoding a corresponding input signal into a respective time encoded signal stream from which a respective archetype matrix is derived. A plurality of features are selected and excluded from the archetype matrices to generate corresponding archetype exclusion matrices. An input signal exclusion matrix is generated from the input signal matrix and each of the archetype exclusion matrices. The input signal exclusion matrix is compared with each of the archetype exclusion matrices to generate an output identifying the input signal.

Abstract: A signal processing system for time varying band-limited signals such as speech comprises signal coding means for affording a time encoded signal symbol stream, a matrix generator for generating a fixed size, typically "A" matrix from the symbol stream, and an artificial neural network to which the matrix elements are applied for network training and subsequently for affording an output indicative of the nature of an input signal.