Opinion ID: 1193824
Heading Depth: 3
Heading Rank: 4

Heading: The Admissibility of Voice Spectrograph Evidence under Daubert

Text: On remand, the trial court found that Cain's testimony regarding the applied forensic technique of using spectrography to analyze and identify voices was admissible under both Frye and Daubert. Coon and the APDA contend that the trial court erred in finding Cain's testimony regarding voice spectrography admissible under either test. Given our adoption of Daubert in Part III.C, there is no reason to review admissibility under Frye.
We review a trial court's ruling on the admissibility of expert testimony for abuse of discretion. [71] Although the parties agree on this standard of review, two amici curiae, Butler and the APDA, argue that we should review de novo a trial court's decision to admit or exclude scientific evidence. So arguing, APDA relies on a passage from Pulakis, where we stated that [o]n the basis of our study of the judicial authority and academic literature in this area, we conclude that the results of polygraph examinations should not be received in evidence over objection. [72] In addition, both Butler and APDA cite Contreras, in which the court of appeals stated that it was free to exercise [its] independent judgment when reviewing the trial court's decision to admit evidence recovered from an eyewitness during hypnosis because the findings regarding memory and the effects of interrogative techniques on eyewitness testimony and hypnosis in general are legislative facts, rather than adjudicative facts. [73] Kesan and the dissenting opinion propose adopting a hybrid standard of review, reviewing de novo a trial court's findings on the scientific knowledge prong of the Daubert test and retaining an abuse of discretion standard for the second prong relating to relevance or fit of the facts of the particular case to the scientific technique employed. [74] They assert that implementing de novo review of scientific validity allows for more uniform adjudication at the trial and appellate levels, and for development of distinct validation criteria for expert testimony relating to different scientific or technical disciplines. [75] We see no present reason to adopt a new or hybrid standard for reviewing rulings on the admissibility of scientific evidence. Abuse of discretion is the standard applicable to other evidentiary rulings. [76] Such rulings are best left to the discretion of the trial court. A determination of reliability under Daubert is no different. The dissent reaches a different conclusion because it begins with the premise that the scientific validity of a technique is a legal issue which does not turn on case-sensitive facts. [77] This premise does not adequately take account of the reality of the judicial process and the variable state of science. The New Mexico Supreme Court rejected the same argument advanced here by the dissent. In rejecting the de novo standard of review that court noted: This reasoning assumes, however, that the record on appeal contains all of the relevant, most recent data concerning the scientific method, and that assumes too much. It also assumes that there is always a reservoir of scientific literature that an appellate court might independently reference in a de novo review. The abstract validity of a scientific technique should not vary from court to court, but how the proof of such validity is communicated will often vary from presentation to presentation. Some experts are more skillful and more well-informed than others just as some lawyers are more skillful and more well-prepared than others. In addition, the state of science is not constant; it progresses daily. For example, what might have been true about [post traumatic stress disorder] in the early 1980s when it was first addressed in published opinions might not have been true in 1992.... [78] We recognize that different trial judges, in exercising their discretion, may reach different conclusions about scientific reliability. But we disagree with the dissent's suggestion that the inconsistency will be of such magnitude as to compromise the integrity of the judiciary in the eyes of the public. [79] Despite such predictions in the academic literature, the majority of the federal circuits have chosen to apply the abuse of discretion standard when reviewing district court decisions under Daubert. [80] In addition, the Supreme Court recently approved the abuse of discretion standard in General Electric, Co. v. Joiner, 522 U.S. 136, 118 S.Ct. 512, 517, 139 L.Ed.2d 508 (1997). The principal reason for adopting the Daubert standard is to give the courts greater flexibility in determining the admissibility of expert testimony, so as to keep pace with science as it evolves. We think the abuse of discretion standard of review best comports with these aims, and we choose to apply it here.
In making its findings on remand, the trial court discussed each factor the Supreme Court articulated in Daubert. The trial court found that the technique of spectrographic voice identification had been empirically tested on numerous occasions by many scientists during approximately the past twenty years. The court determined that voice spectrography had been subjected to peer review and publication, but noted that the technique's reliability was debated in the scientific literature. It also found that when properly performed under the stringent standards of the International Association for Identification by a qualified, trained scientist or technician, voice spectrography has a known error rate of less than one percent. The trial court found that because voice spectrography has been subjected to empirical testing, it is both falsifiable and refutable, and that testing has not refuted the technique or shown that it is falsified. The court determined that when voice spectrography is properly performed by a qualified person, it has attained widespread acceptance within the relevant scientific communityamongst forensic scientists and scientists in acoustics and speech-related fields with experience using the technique. The trial court also found that the reasoning and methodology underlying Cain's testimony were scientifically valid, and that Cain had properly performed the voice spectrographic analysis in this case. The trial court stated that Cain's testimony was relevant in that it assisted the jury in determining a key issue at trial, namely the identification of the person who left the threatening messages on Deborah Rudolph's answering machine. The trial court therefore concluded that Cain's testimony was sufficiently relevant and reliable to be admitted under Daubert. The trial court made these findings on remand after reviewing the record, including Cain's testimony. Because this is our first review of a trial court's application of Daubert, we discuss Cain's evidence at some length. Cain testified at the 1992 hearing about his qualifications as a voice spectrograph expert. He has a bachelor of science degree in engineering and two master's degrees in forensic science; he had completed two years of work toward a doctoral degree in criminology. He had continued his post-graduate education by attending seminars at the state and national levels dealing with tape examination and other aspects of forensic evidence analysis. He had given talks and seminars throughout the United States on voice identification and tape analysis and had published a number of articles concerning the legal aspects and results of research studies on the reliability of voice spectrograph analysis. He owned and operated Applied Forensic Technologies International, Inc., a forensic laboratory that analyzes physical evidence. Before opening his private laboratory, Cain worked for ten years as a document and voice print examiner for the Secret Service in its Washington, D.C., crime laboratory, and for three years for the Internal Revenue Service as a supervisor at its Illinois Crime Lab, where he started a voice identification program. He was certified by the International Association for Identification (IAI) as a voice identification specialist and he served on the certification board of that organization. Based on this testimony offered outside the jury's presence, the trial court found that Cain was qualified as an expert under Alaska Evidence Rule 702 in the field of applied forensic techniques of voice prints. Cain then explained that in performing a voice analysis, he conducts both an aural and a spectrographic analysis of a voice. Cain discussed factors which might affect the results of voice analysis, the potential error rate of voice analysis, and the reliability of the technique. He described the standards adopted by the IAI in 1992, and stated that he adhered to these standards, and that he sends his work to another examiner for an independent review of the accuracy of his findings. Cain estimated that approximately thirty-one to thirty-four states have accepted voice spectrograms, commonly known as voiceprints, as a positive means of forensic identification. Cain testified that voice spectrographic analysis has been subjected to empirical testing from the time of its inception over twenty years prior. Cain testified about various scientific studies that concluded that voice spectrographic analysis was a valid and reliable forensic identification technique. The scientific literature submitted to us by amicus APDA would also support a finding that spectrographic analysis has been empirically tested. We conclude that the trial court did not err in finding on remand that this technique has been subjected to empirical testing. Cain conceded that several studies question the validity and reliability of the technique. Although many of the studies questioned the reliability of the technique, the trial court did not err in finding on remand that the technique had been subjected to peer review and publication, since a general consensus is not a mandatory requirement under Daubert. Cain also testified that research studies have calculated the known error rate for voice spectrographic analysis to be less than one percent when the technique is performed properly by a scientist skilled in the technique. [81] Cain stated that in order to make the sample as accurate as possible by eliminating intraspeak variation (the internal factors that affect a person's voice, such as the time of day, the amount a person has eaten, or the person's mood), the scientist conducting the analysis should take numerous exemplars and attempt to duplicate the conditions of the original recording. The trial court did not err in finding on remand that the known error rate for voice spectrographic analysis performed properly by a skilled scientist in the field was sufficiently low to make this evidence reliable. General acceptance remains a factor under Daubert. The trial court on remand found that [t]he technique of voice identification using spectrography when properly performed by a qualified person has attained widespread acceptance within a relevant scientific communityforensic scientists and scientists in acoustics and speech related fields who had experience using the technique. In determining the admissibility of voice spectrograph evidence under the general acceptance test, several courts have defined the composition of the relevant scientific community. In State v. Gortarez, 141 Ariz. 254, 686 P.2d 1224, 1233 (1984), the Arizona Supreme Court defined the relevant scientific community as disinterested and impartial experts in many fields, possibly including acoustical engineering, acoustics, communications electronics, linguistics, phonetics, physics, and speech communications. The Gortarez court noted that this list was merely suggestive and not all-inclusive. [82] Neither party questions the trial court's determination of the relevant scientific community in this case. Based upon the findings of other courts as to the relevant scientific community for the technique of forensic voice identification using spectrography, we conclude that the trial court did not abuse its discretion in determining the relevant scientific community. Coon and the APDA argue that voice spectrograph analysis is not generally accepted within the relevant scientific community, and has been ruled inadmissible by numerous courts applying Frye. The APDA has submitted several articles questioning the reliability of voice spectrograph analysis when used as anything other than an investigative tool. The APDA also included a copy of an Alaska superior court decision in State v. Gomez, No. 3AN-S88-5190 Cr. (March 23, 1990), in which Superior Court Judge Joan M. Katz found that voice spectrographic identification evidence was inadmissible because it was not generally accepted within the relevant scientific community. In determining whether evidence is generally accepted within the scientific community, courts have generally looked to three sources for guidance: (a) judicial opinions; (b) scientific literature; and (c) expert testimony presented at an evidentiary hearing. [83] Under Frye many courts have determined that voice spectrographic evidence is not admissible. [84] But other courts have allowed voice spectrographic evidence under standards other than Frye. [85] And several courts purporting to apply Frye have also allowed such evidence. [86] Overall, it is inconclusive whether there is a judicial consensus that voice spectrographic evidence is generally accepted within the relevant scientific community. The scientific literature cited by the APDA permits a conclusion that there is significant disagreement among experts in the field of voice spectrographic analysis regarding the reliability of the technique. As the State notes, no scientific literature was submitted to the trial court for review, but Cain testified about several articles and studies addressing voice spectrographic analysis, and conceded that the reliability of the technique was disputed among members of the relevant scientific community. Cain cited, among others, a study conducted in 1986 by Bruce E. Koenig of the Federal Bureau of Investigation. Koenig there noted that in a survey of 2,000 voice identification comparisons made by FBI examiners under actual forensic conditions, meaningful decisions were made only 34.8% of the time, with a known error rate of 0.31% for false identifications and 0.53% for false eliminations, with an overall error rate of 0.43%. [87] In a 1993 article, Koenig noted that problems still persist in the spectrographic voice identification field, such as separate sets of certified examiners making high confidence decisions for both identification and elimination in the same case. [88] Koenig also stated that even with the establishment of new standards by the IAI in 1992, the use of spectrographic voice technique is on the decline, and [t]he most important legal difference is the FBI's policy not to provide testimony on spectrographic comparisons due to the inconclusive nature of the examination and the unknown error rate under specific investigative conditions. [89] Although it is not clear that voice spectrographic analysis has attained general acceptance within the relevant scientific community, we do not find that the trial court clearly erred in making its general acceptance finding, or abused its discretion in ruling that the evidence satisfied Daubert. Consequently, we conclude that the trial court did not err in finding the voice spectrographic evidence admissible under Daubert. It therefore did not abuse its discretion in admitting this evidence at Coon's trial.