Smartphone sensors could be used to help determine a person’s level of alcohol intoxication based on changes in their voice, a study has found.
Researchers at Stanford Medicine and the University of Toronto conducted a small study of 18 adults aged 21 or over. Participants were given a weight-based dose of alcohol and randomly assigned a series of tongue twisters – one before drinking, and one each hour up to seven hours after drinking.
The participants were asked to read the tongue twister aloud, and a smartphone was placed on a table 1-2ft away to record their voices.
Researchers also measured their breath alcohol concentration at the beginning of the study and every 30 minutes for up to seven hours. They used digital programs to isolate the speaker’s voices, broke them into one-second increments and analysed measures such as frequency and pitch.
When checked against breath alcohol results, changes in the participants’ voice patterns as the experiment went on predicted alcohol intoxication with 98 per cent accuracy.
“The accuracy of our model genuinely took me by surprise,” said lead researcher Brian Suffoletto. “While we aren’t pioneers in highlighting the changes in speech characteristics during alcohol intoxication, I firmly believe our superior accuracy stems from our application of cutting-edge advancements in signal processing, acoustic analysis and machine learning.”
The researchers hope the technology could be used to deliver “just-in-time interventions” to prevent injury and death resulting from motor vehicle use or other accidents while intoxicated.
“While one solution could be to frequently check in with someone to gauge their alcohol consumption, doing so could backfire by being annoying (at best) or by prompting drinking (at worst),” Suffoletto added.
“So, imagine if we had a tool capable of passively sampling data from an individual as they went about their daily routines and surveilling for changes that could indicate a drinking episode to know when they need help.”
He said that surveillance tools may eventually combine several sensors such as gait, voice and texting behaviour to make a determination about intoxication levels.
Much larger studies need to be done on people with a wide variety of ethnic backgrounds to confirm the validity of voice patterns as an indicator of intoxication, the researchers said.
