INTRODUCTION
The forensic science of voice identification has come a
long way from when it was first introduced in the American courts back in the mid 1960's.
In the early days of this identification technique there was little research to support
the theory that human voices are unique and could be used as a means for identification.
There was also no standardization of how an identification was reached, or even training
or qualifications necessary to perform the analysis. Voice comparisons were made solely on
the pattern analysis of a few commonly used words. Due to the newness of the technique
there were only a few people in the world who performed voice identification analysis and
were capable of explaining it to a court. Gradually the process became known to other
scientists who voiced concerns, not as to the validity of the analysis, but as to the lack
of substantial research demonstrating the reliability of the technique. They felt that the
technique should not be used in the courtroom without more documentation. Thus the battle
lines were drawn over the admissibility of voice identification evidence with proponents
claiming a valid, reliable identification process and opponents claiming more research
must be completed before the process should be used in courtrooms.
Today voice identification analysis has matured into a
sophisticated identification technique, using the latest technology science has to offer.
The research, which is still continuing today, demonstrates the validity and reliability
of the process when performed by a trained and certified examiner using established,
standardized procedures. Voice identification experts are found all over the world. No
longer limited to the visual comparison of a few words, the comparison of human voices now
focuses on every aspect of the words spoken; the words themselves, the way the words flow
together, and the pauses between them. Both aural and spectrographic analysis are combined
to form the conclusion about the identity of the voices in question.
The road to admissibility of voice identification evidence
in the courts of the United States has not been without its potholes. Many courts have had
to rule on this issue without having access to all the facts. Trial strategies and budgets
have resulted in incomplete pictures for the courts. To compound the problem, courts have
utilized different standards of admission resulting in different opinions as to the
admissibility of voice identification evidence. Even those courts which have claimed to
use the same standard of admissibility have interpreted it in a variety of ways resulting
in a lack of consistency. Although many courts have denied admission to voice
identification evidence, none of the courts excluding the spectrographic evidence have
found the technique unreliable. Exclusion has always been based on the fact that the
evidence presented did not present a clear picture of the technique's acceptance in the
scientific community and as such, the court was reluctant to rely on that evidence. The
majority of courts hearing the issue have admitted spectrographic voice identification
evidence.