Identification of individuals by the sound of their voices has long been an accepted courtroom practice. It has been accompanied directly both in the courtroom and extra-judicially, as well as indirectly with sound recordings. Voice identifications are essential to authenticating sound recordings for introduction as evidence, and are frequently the most conclusive evidence in certain types of criminal prosecutions such as those involving obscene phone calls. Until recently all voice identifications were made by the human ear, by someone familiar with the sound of the voice being identified. Although generally accepted by the courts, it has been recognized that such identifications are occasionally quite unreliable. At least one court has suggested that "a highly desirable aid to judicial determinations of truth" would be a scientific method of voice identification, which is not subject to human frailties.
Bernard S. Kamine,
The Voiceprint Technique: Its Structure and Reliability,
San Diego L. Rev.
Available at: https://digital.sandiego.edu/sdlr/vol6/iss2/4