Voice stress analysis

YOKNAPATAWPHA COUNTY SHERIFF'S DEPARTMENT

Investigating Officer(s): Det. T. Armstrong, Det. S. Murphy
Incident No.: 000073-05A-2014
Case Description: Cameron & Caitlin Maxwell Homicide Investigation

Voice samples were obtained from some persons of interest to the Maxwell investigation for assessment. Some persons of interest were not available or declined to provide samples.

Subjects were asked a series of control questions to establish baseline laryngeal microtremors affecting vocal pitch, and were then asked to say two test sentences relevant to the investigation.

These test samples were compared against the control samples to identify vocal stressors. Vocal stress frequency is said to increase relative to the baseline during possible dishonesty.

Voice stress analysis findings are not admissible in court, but can be a useful investigative tool in evaluating the veracity of a subject's verbal responses.

Stress Scale

12 Hz High Stress
11 Hz High Stress
10 Hz Average Stress
09 Hz Low Stress
08 Hz Low Stress

Results in the 11-12 Hz range is said to be an indication of dishonesty.