1. A method for processing a speech signal, comprising using at least one computer programmed to implement: dividing the speech signal into a succession of frames; identifying at least one of the frames as an unvoiced click frame; identifying at least one of the frames as an unvoiced non-click frame; identifying at least one of the frames as a voiced frame; calculating one or more parameters of a model of a phase spectrum of the at least one unvoiced click frame; storing the parameters of the model of the phase spectrum of the at least one unvoiced click frame in a data set; applying a first method to the at least one unvoiced click frame and to the at least one unvoiced non-click frame to obtain harmonic representations of the at least one unvoiced click frame and the at least one unvoiced non-click frame; and applying a second method, different from the first method, to the at least one voiced frame to obtain an harmonic representation of the at least one voiced frame, wherein identifying the at least one of the frames as the at least one unvoiced click frame comprises: identifying the at least one of the frames as an unvoiced frame; and processing the at least one unvoiced frame by: analyzing a probability distribution of the at least one unvoiced frame, finding a deviation of the probability distribution of the at least one unvoiced frame from a Gaussian distribution, and identifying the at least one unvoiced frame as the at least one unvoiced click frame if the deviation exceeds a predefined threshold.