The effect of disguise of the fundamental frequency of voice (F0) on other formant frequencies in turkish

Voices, which are deliberately tried to be changed during the speech in order to hide their identities by the speakers, are increasingly being the subject of forensic investigations. Although voice disguise can be done in different ways, one of the simplest method is to change the fundamental frequency, that is, to make the sound low pitch or high pitch. In this study, in which F0, F1, F2, F3 and F4 parameters of normal and disguised recordings of 15 female and 15 male speakers were evaluated, it was aimed to find out which acoustic properties changed and which remained consistent in order to help detect disguised voices. For features affected by voice disguise, the goal is to determine whether these changes are systematic, whether the same change always occurs for a given change condition. It has been evaluated that the results obtained at the end of the study will provide convenience to the experts in judicial and administrative investigations. Keywords: Forensic Linguistics, Forensic Voice Analysis, Voice Disguise, Formant Analysis