Speech analysis has a type called speech stress analysis which detects stress in the form of microtremors in a person's speech. It is important to note that the voice stress analysis is equivalent to the polygraph. Both the polygraph and stress have the common problem of not being able to highlight deception. Nonetheless, speech analysis is apparently used by both the Federal Bureau of Investigations and the United States Central Intelligence Agency. The fact that each person has a unique voiceprint makes it theoretically possible to identify the speaker. This can be achieved through acoustic analysis of pitch meters, pitch and vowel length. When pairs of spectrographs showing the suspected speaker and the known speaker uttering similar words are matched, the speaker can be easily identified (Olsson 2004, p. 71). The fact that vocal stress analysis relies on visual comparison is a big deal. Another issue involves variation that occurs in the speaker itself. It has been reported that uttering the same sentence one hundred times in rapid succession does not produce two identical utterances. Some countries such as the United Kingdom, however, prefer auditory analysis over the acoustic method. In auditory analysis, speech samples are transcribed phonetically. This analysis is important as it allows analysts to identify idiosyncratic features such as speech impediments and unusual realization of phonemes. Additionally, analysts may find the need to profile the speaker's social and regional identity. Nowadays speech analysis accepts the mixed method as the most accurate and reliable. It can find its application in situations... in the middle of the document... and in textual analysis (Gibbons 2003, p. 26). Works CitedCoulthard, M, & Johnson, A 2007, An introduction to forensic linguistics: linguistic evidence, Routledge, New York.Gibbons, J 2003, Forensic linguistics: an introduction to language in the justice system, Blackwell Pub, Malden.Gibbons, J, & Turell, TM 2008, Dimensions of forensic linguistics, John Benjamins Publishing Company, Amsterdam.Jordan, SN 2002, Forensic linguistics: the linguistic analyst and expert witness of linguistic evidence in criminal trials, Biola University, La Mirada.McMenamin , GR, & Choi, D 2002 Forensic Linguistics: Advances in Forensic Stylistics, Crc Press, Boca Raton.Olsson, J 2008, Forensic Linguistics, Continuum, London.Olsson, J 2004, Forensic Linguistics: An Introduction to Language, Crime and to the Law, Continuum International Publishing Group, London .