1. A method for measuring a disparity between two speech samples, comprising: recording a reference speech sample spoken by a native speaker; recording a speech sample spoken by a language student; generating digital data files representative of the reference and student speech samples, thereby providing a reference speech data file, and a student speech data file, the speech sample data files including information indicative of sound intensity levels as a function of time over the chronological durations of the respective speech samples; segmenting the reference and student speech data files into respective reference and student speech-unit data files, with each said speech-unit data file including a sequence of speech units over its speech sample duration; determining a duration disparity between a first speech unit and a second speech unit, that is not adjacent to said first speech unit, within the reference speech-unit data file, thereby providing a reference speech-unit duration disparity; determining a duration disparity between first and second speech units in the student speech-unit data file that correspond to the locations in the sequence of speech units of the first and second speech units in the reference speech-unit data file, thereby generating a student speech-unit duration disparity; and calculating a difference between the student speech-unit duration disparity and the reference speech-unit duration disparity.