ABSTRACT
In the review on audio and visual evidence 2001-2004, this chapter presents two separate papers. The first paper presented a very detailed description of the fields of expertise in audio analysis, speaker identification, and linguistic authorship. The second paper presented a general overview of the many different types of forensic investigations on visual evidence and a way to categorize them into three general fields of expertise: imaging and video technology, crime scene photography, and biometric identification. The primary domains of forensic audio analysis are authentication, speech enhancement, transcription of linguistic content/disputed utterance examination, and the analysis of non-speech events. The main goal of speech enhancement is to enable more accurate and more efficient transcriptions of the speech and non-speech events in a low-quality recording. Formant frequency measurements in forensic speech analysis have been approached from different directions. The most classical method is the measurement of the centre frequencies of different phonetic/phonological vowel categories in a language.
