Brickhouse offers this portable voice lie detector that is probably the first hand-held voice tension detector. This palm-sized lie detector analyzes voice stress to detect lies. It has a display so it can show you Demon icon’s nose and horns grow when someone tells a lie.
To train the Portable Voice Lie Detector to the human voice, ask your subject 3 yes/no questions and then record the voice to establish a baseline. Then ask the real yes/no questions and watch the figure on the screen. The devilish figure’s nose will grow and his horns will appear. The greater the tension in the voice, the longer his nose and horns will be.
Brickhouse is selling this lie detector for $49.95.