Voiceprint, also called speech spectrogram, is a visual record of the sound waves of a human voice. Voiceprints and tape recordings of the voices of several people are sometimes compared to identify a certain person’s voice. However, some scientists question the reliability of this method as a means of identification. Voiceprints are also used in the study of speech and hearing disorders.
Some police departments use voiceprint evidence in criminal cases. They believe the voiceprint method is reliable as a method of identification when used in combination with tape recordings. Voiceprints often have been used to clear of wrongdoing people who have been suspected of such crimes as extortion and the making of obscene telephone calls. Voiceprint evidence has been admitted in many criminal cases. But some experts believe voiceprints are difficult to interpret and are not accurate enough for use in court.
Voiceprints are made by running a tape recording of a voice through an instrument called a sound spectrograph. A voiceprint shows the duration of spoken words and the loudness, pitch, and quality of the recorded voice.
Three American scientists at the Bell Research Laboratories first developed the sound spectrograph in the 1940’s. The American physicist Lawrence G. Kersta and the American audiologist Oscar I. Tosi later contributed to the development of voiceprints as a means of identification.