1. A computer implemented method of creating a speech parameters reference database for classifying speech utterances according to various behavioral, psychological and speech styles characteristics, said computer implemented method comprising: selecting manually a certain speaking context; selecting manually the behavioral, psychological and speech styles characteristics to be analyzed in the selected context; obtaining a plurality of speech utterances of people in the selected context; grouping manually the speech utterances into groups representing similar behavioral, psychological and speech styles characteristics; pre-processing each of the speech utterances in said groups of utterances representing similar behavioral, psychological and speech styles characteristics, into silent and active speech segments; dividing the active speech segments into strings of equal length blocks, said blocks having primary speech parameters including pitch and amplitude parameters; deriving a plurality of secondary speech parameters from the primary speech parameters, wherein said plurality of selected speech parameters includes at least one one of: the sum of segments per time unit of equal-pitch, rising-pitch and falling-pitch trends in said strings of blocks, and the average lengths of segments of equal-pitch, rising-pitch and falling-pitch trends in said strings of blocks; and determining unique secondary speech parameters, parameter combinations and parameters' values that are common to each group of utterances from said secondary parameters, wherein said unique secondary speech parameters represent the typical behavioral, psychological or speech styles characteristics of each group.