NAS 1979 Report
Definition
The National Academy of Sciences report 'On the Theory and Practice of Voice Identification,' which concluded that spectrographic voice identification lacked the scientific foundation to support forensic individualisation claims, including standardised criteria, independent proficiency testing, and validated error rates.
Related terms
- Daubert Standard
- The US federal evidentiary standard (Daubert v. Merrell Dow Pharmaceuticals, 1993) requiring that expert testimony be based on scientifically valid methods with...
- ENFSI BPM
- The ENFSI Best Practice Manual for Forensic Comparison of Speech (2015, rev. 2022); the operational standard for speaker comparison in European forensic...
- Formant
- A resonance peak in the vocal tract filter; F1 and F2 together characterise vowel quality (height and frontness), while F3 and higher...
- Frye Standard
- The US legal test for admissibility of scientific evidence, originating from Frye v. United States (1923), which required that a technique be...
- IAVI (International Association of Voice Identification)
- Organisation founded by Kersta in the late 1960s to train and certify forensic voice identification examiners in the spectrographic comparison method. Certification...
- Likelihood Ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- Proficiency Testing
- An external quality assurance programme in which a laboratory analyses blind samples distributed by an independent provider and submits results for comparison...
- Sound Spectrograph
- An instrument that plots the frequency content of a speech signal over time, with frequency on the vertical axis, time on the...
- Voiceprint
- Lawrence Kersta's 1962 term for the claim that the spectrographic pattern of an individual's speech is unique enough to serve as a...
Explained in
- Spectrographic Voiceprint History and Its Modern RejectionThe National Academy of Sciences report 'On the Theory and Practice of Voice Identification,' which concluded that spectrographic voice identification lacked t...