1. An automatic process for the identification by ultrasound of a defect of a determined type in a part, said process comprising the steps of producing an ultrasound image of said part by sweeping the part with at least one beam of ultrasound waves, recording point-by-point the amplitude of the reflected or diffracted ultrasound wave for each point to produce a corresponding recorded value for that point, constructing an ultrasound image for which the amplitude of the signal at each point is proportional to said recorded value for that point; and analyzing said ultrasound image to recognize the presence of said defect by filtering said ultrasound image to eliminate signals whose amplitude is less than a determined threshold, said threshold being a function of the nature of said defect, thereby producing disjoint zones corresponding to ultrasound reflectors, extracting the contours of said disjoint zones to create objects, establishing a list of objects of said filtered image with each object being defined geometrically by its contour, characterizing each object by determining for each object, attribute values of a predetermined list of attributes characterizing an object, comparing for each object, the determined values of said attributes to minimum and/or maximum values determined in the course of a learning phase on sample parts in which said defect is present and identified by a specialist, so as to identify the defect in the part.