Evidentiary Use of the Voice Spectrograph ill Criminal Proceedings

• Author: Major Delroy J. Gorecki
• Pages: 05

A sophiaticated method of identifying the speaker of a voice exemplar through analysis of voice patterns has evolved since World War I1 This technique, known as speech spectrography, is easentially the transformation of speech into a graphic display or spectrogram by means of an instrument known as a spectrograph Identificatmn of a speaker is made bra trained examiner's comparison of the spectrograms of known and unkrmvn voice samples, as well as by aural comparison of the samples. Depending upon the number of point? of similarity or dissimilarity found. the examiner will announce either that the samples iiere or were not made by the same person, or that he 1s unable to state whether rhe NO voice samples mere created by the Fame individual. This comment explores the raried theories courts ha\e used to determine nhether evidence inralnng voice spectrograph) should be admitted in cnminal proceedings

ahich is typically attributed to the creator of an unknmin i d e e exrnplar there are undwstandably few mistitutmial attacks diiecteil at the proce.5 of obtaining or the actwai use of an unknown voice exernplai LII the

Because of the anon>mous criminal conduct

defendant violates neither the Constitution nor a state privacy of eoinmuiiicatian law despite the fact that iurreptitiaus rneanr aere used to obtain the known exemplar of the ilefenriant'i \ o m search warrant or court ortiered wiretap can also be uwil to ohta defendant's raice exemplar. whether or not the inrlirirlual is 12 tody.' Indeed. where the defendant LS in custoilv or under the iur-

19i71 VOICE SPECTOGRAPH

isdiction of a court, the preferred procedure is to secure a court order compelling him to give an exemplar.$

If and when the unknown voice is found to be among the knorrn exemplars through the voice spectiogiaph identification process. and the constirutional issues hare been resolved. the crucial ques-tion becomes uhether or not the particular court ail1 permit the eridentiarr use of the voice wectroeraah. >laterialitr or relevam

. I . problems aside, all courts require the satisfaction of certain legal standards before allowing the introduction or use of scientific eri~lence.~

The standard imost frequently utilized by courts in eonsidering the admissibility of scientific evidence is found in the following

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Criticisin has been leveled at the rigidit) of the Frye scientific standard both generally and with respect to its application to the ioice spectrograph technique.12 When faced with the choice of either modifying the Fr,#r standard or excluding uhat is vieaed as important probative evidence, several courts have ignored Fryr, others hare applied 11 in modified form, and athere hare utilized the strict teit. only to arrive at opposite conelueions. An emerging trend in the federal courts is to adopt an earl) view of the United States Cowt of Mihtary Appeals and the Florida District Courts of Appeal and admit the apectrograph related material into evidence. However. this trend is not universal, and the California Supreme Court and the United States Court of A 883s lo, the Dirtiict of Columbia Circuit hare ignored these ca

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admitteri A B S Prop1

originating in Peopl fronted with the issue

accuiac) dnd reliabiliti of rhir device has become established anti

The iirrt cyiminal case of record in which voiceprint e\irIence wab

same person.

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19iil VOICE SPECTOGRAPH

into evidence. The admissibilit! vas not judged b) the FI,#E standard of "general scientific acceptance in the fiekr': rather the board upheid the admission of the eipert testimony concerning the loice~ n n t on the basis of "the ii.ell-establisher1 rule which eires the trial judge in a criminal case wide discretion in determining the qualificationi ani1 competency of an expert witness." Indeed, the board noted that it "heaitate[cll to conclude . . . that Ithe technique had1 gained 'general acceptance'. . . .'',19 and noted that its tlecicioii was not meant to signal a departure from the Fiya rule nith respect to lie detector testsz0

The Court of Niiitarj- .ippeals affirmed. stating "Courts have consistently recognized the admiaribility of the testimony of experts in areas ~5 here there 1s neither infallibility of result nor unanimity of opinion . .''21 and that the provirion of the llama1 for Courts-llartial Ahich dealt iiith expert witnesses hail been complied nith:

ence, or ha8 kr

hich ire EO: generatl"" mri experwnceAlthough txo expert iiitiiesies in the field of speech transmission and voice recordings had expressed reservations about the reliability of the voiceprint technique followed in this case, and disaentmg Judge Ferguson pointed out the faailure of the technique to satisfy the F ~ u e scientific standard the court said it is only necessary to

d further !hat t,e URS pe

eompaniar? of i0"lld pat

NILITARY LAW REVIEW [YOL 77

ear. That basis of voice spectrupraph admisiibilit! is established b! the cases that follou in which the piocess iiar o 4 in conjunction uith other evidence bearing on the identification of an accused Far It 1s identification. and not necessarily innocence or guilt. that i~ at issue in the voice specrrograph identification process.

the wue of voiceprint arlmizaibilit) was finally decided At trial. Car? had refused to supply a requested voice exemplai so thar a...