1. A signal processing arrangement for a time varying band-limited input signal, comprising: means for receiving a time varying band-limited input signal; means operable on said input signal for generating a time encoded signal symbol stream from said input signal; means operable on said symbol stream for deriving from said stream a fixed size matrix indicative of said input signal; means for storing a plurality of archetype matrices corresponding to different input signals to be processed, each of said archetype matrices being generated by coding a corresponding one of said different input signals into a respective time encoded signal symbol stream and coding each said respective symbol stream into a respective archetype matrix; means operable on all said archetype matrices for selecting a plurality of features of said archetype matrices; means operable on each of said archetype matrices for excluding from said archetype matrices said selected features to generate corresponding archetype exclusion matrices; means operable on said input signal matrix and on each of said archetype exclusion matrices to generate an input signal exclusion matrix; means for comparing the input signal exclusion matrix with each of the archetype exclusion matrices and for generating an output indicative of said input signal, said output identifying the input signal and discriminating said input signal from other vibrational time varying inputs.