Date of Award


Degree Name

Master of Science


Communication Disorders and Sciences

First Advisor

Muzio, Diane


The purpose of this single-subject case study was to determine if vocal changes can be used to implicate deceit based on a suspect’s involuntary vocal responses when placed in a high stress situation such as being interrogated for a crime. This study also identified justification for the use of SLPs in the criminal justice system for the purpose of voice analysis. 10 truthful and 10 deceitful statements were analyzed from a suspect charged with the crime of murder using the voice analysis software Praat to determine differences in vocal attributes with varying speech characteristics. These statements were analyzed in the areas of intensity, hesitations/pausing, speech rate, and disfluencies. It was found that changes in maximum intensity and total number of words per statement implicate that a person is being deceitful.




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