The lie detector test by telephone is quick and inexpensive
A test using voice analysis is nowhere near as safe as many sensors are missing, but it is certainly possible.
Lie detector tests can be performed in a variety of ways, including polygrpah (also known as a "lie detector") tests, which monitor physical reactions such as heart rate, breathing and skin conductivity, and Voice Stress Analysis (VSA), which analyzes the changes in vocal patterns such as tension, pitch and pauses. We also have lie detector tests that are carried out over the telephone, these are called Remote Voice Stress Analysis (RVSA) and they use the same technology as the VSA, which are carried out over a telephone. They work by recording the subject's voice and analyzing changes in vocal patterns, which are seen as indicators of stress and lying. However, it is important to note that the reliability of polygraph tests, including the RVSA, is controversial and they are not admissible as evidence in court proceedings as they are not 100% reliable.
A lie detector test by telephone offers significantly fewer measuring points and security than a professional lie detector test with all sensors. Nevertheless, this is a cheap and quick way to uncover at least gross lies. We speak to the person being tested Telephone about very general things in order to maintain the normal voice pattern and to be able to recognize deviations in the questions later.