The research began by methodically examining the anatomical, physiological, and physiopathological characteristics of speech and the respiratory system to determine if it would be possible to identify a speaker's sex and identity. The next aim of research was to develop a system for identifying a person from his or her speech. In the examination, the questioned and comparison voices are transcribed by sonagraph in the form of diagrams which may be of the comprehensive, wide band, narrow band, or contour type. A comparative analysis is then carried out at the voice and speech levels. Since 1972, the Bucharest Criminalistic Laboratory has carried out a large number of criminalistic examinations, 99 percent of which have been upheld by the courts. Using the Romanian method, it is possible to establish whether a questioned sound recording is genuine, determine the sex of the speaker, identify a person from speech and voice in normal conversation, and detect and prove attempts to disguise or imitate voice or speech. To increase the speed with which analyses are performed, a computer program was developed to carry out all the operations, most importantly, calculation of a function for estimating the acoustic characteristics established by the sonagrams. In addition, optical laser filtering is being used for the analysis and synthesis of voice diagrams. 5 footnotes.