Vocal Clues to Deception
Excerpts taken from Telling Lies
While most liars pay careful attention to the words they use, liars often accidentally leak deception clues through their vocal tone and speech patterns. These vocal cues to deception can provide insight into emotional states and lying behavior.
Pauses and Speech Errors
The most common vocal deception clues are pauses. The pauses may be too long or too frequent. Hesitating at the start of a speaking turn, particularly if the hesitation occurs when someone is responding to a question, may arouse suspicion. Likewise, many shorter pauses during the course of speaking, if they occur often enough, may indicate vocal stress and lying.
Speech errors may also be a deception clue. These include:
- non-words: such as “ah”, “aaa”, and “uhh”
- repetitions: such as “I, I, I mean I really…”
- partial words: such as “I rea-reaaly liked it”
These speech patterns and deception clues can occur for two related reasons. The liar may not have worked out their line ahead of time. If they did not expect to lie, or if they were prepared to lie but didn’t anticipate a particular question, they may hesitate or make speech errors. However, these can also occur when the line is well prepared. High detection apprehension may cause the prepared liar to stumble or forget their line. Detection apprehension may also compound the errors made by the poorly prepared liar. Hearing how badly they sound may make a liar more afraid of being caught, which only increases their pauses and speech errors. Deceit may be revealed also by the sound of the voice. While most of us believe that the sound of the voice tells us what emotion a person feels, scientists studying the voice are still not certain about many of the details.
Vocal Signs of Emotion: Pitch, Volume, Cadence
Three vocal signs of emotion can offer additional insight into deception.The best documented vocal sign is pitch. For about 70% of studied individuals, pitch becomes higher when upset, particularly when anger or fear is involved. There’s some evidence that pitch drops with sadness or sorrow, but that is not as certain. Other signs of emotion, not as well established, but promising, are changes in volume and cadence. Often louder, faster speech is associated with anger or fear and softer, slower speech with sadness. These patterns underscore how vocal leakage can reveal emotions despite a liar’s efforts to conceal them.
Concealing emotion in deceit
Changes in the voice produced by emotion are not easy to conceal. If the lie is about emotions felt at the very moment of the lie, then there’s a good chance for leakage. If the aim of the lie was to conceal fear or anger, the voice may sound higher and louder, and the rate of talk may be faster. Just the opposite pattern of voice changes could leak feelings of sadness that deceivers are trying to conceal.
The sound of the voice can also betray lies based on the feelings produced by lying.
Detection apprehension can produce in the voice the sounds of fear. Deception guilt might be shown to produce the same changes in the sound of the voice as sadness, but that is only a guess. It is not clear whether duping delight can be isolated and measured in the voice. I believe that excitement of any kind also has a particular vocal signature, though many of these details have yet to be established.
Falsifying emotions
While words are made for fabricating, it is not easy for anyone, truthful or not, to describe emotions in words. It is the voice, the body, the facial expression that give meaning to the verbal account of an emotion. I suspect that most people can put on the voice of anger, fear, distress, happiness, disgust, or surprise well enough to fool others. While it is very hard to conceal the changes in the sound of the voice that occur with these emotions, it is not so hard to falsify them. Most people probably are fooled by the voice.
Myths about the voice in deception
One of the common myths about vocal deception is that a raised pitch always indicates lying. Raised pitch alone is not a sign of deceit. It could be a sign of fear or anger, perhaps also of excitement. The problem for the lie catcher is that innocents also are sometimes emotionally aroused, not just the liars. Read about deception detection errors for more information.
It’s essential to understand that many vocal clues are related to stress or emotional fluctuations rather than lying itself. This means lie catchers must carefully analyze the context in which vocal and nonverbal cues to deception occur. For more insights, explore the intersection of facial expressions and lying, micro expressions, and body language and lying to complement voice analysis.
