Can people tell if someone is drunk based on slurred speech?

Some Studies on the Relationship Between Slurred Speech and Intoxication 

Drunken Driving AttorneyIn this study, male talkers uttered sentences while sober and then in an impaired state. They were recorded, and then the recordings were used for two experiments. First, the researchers listened to the two different recordings to determine whether there were differences in the way the men spoke when sober versus when impaired. Then, the recordings were played for college undergraduates, as well as Indiana State Troopers, who were asked to judge whether individual sentences were produced by a sober or an intoxicated speaker. While the first test found differences in people’s speech between sober and impaired states, the second found that both the students and the police officers were poor judges of whether speech was produced by a sober or drunk individual.

Similarly, another study found that speech patterns do not always show whether or not a person is impaired by alcohol. While most of the subjects in this study exhibited changes in speech as their BAC rose, nearly one-fifth of them spoke in a similar fashion regardless of BAC.

Can machines tell if people are drunk?

In another test, eleven individuals recited a text twice, once when sober and once after becoming intoxicated. The researchers then used statistical analysis to evaluate various speech parameters. The results showed that acoustic analysis is not useful in determining whether or not the person speaking was drunk or sober while being recorded.

Can people be fooled?

This experiment involved the use of actors, who were asked to say certain things while pretending to be drunk, while actually drunk, and while trying to sound sober when actually at the highest level of intoxication. Those who listened to them rated the level of drunkenness of the actor based on the audio. The results showed that listeners thought that sober individuals were intoxicated 88% more often than they thought actually impaired individuals were drunk. Additionally, when drunk actors pretended to be sober, they were judged as sober 61% more often than actually sober ones were.

As evidenced by these studies, speech is poor proof of intoxication, and yet courts continue to use it as evidence. To learn how you can defend yourself against unreliable evidence when you have been charged with DWI, fill out the form on this page for a free consultation with experienced New Jersey DWI attorney Dan T. Matrafajlo.


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