"Half of the speakers for each sex reported that they had sexual intercourse with a person outside of a previous or current, exclusive and committed relationship at some point in their lives (i.e., were 'cheaters'), and the other half reported never cheating on their partners," the study noted.
To ensure that the voice samples were as similar as possible, all of the voices used were from people who reported being heterosexual, white, unmarried and in a committed romantic relationship.
The researchers created two versions of each voice recording - a higher-pitch version and a lower-pitch version -to determine whether pitch played a role in how these voices were perceived. Participants then rated the voices on a scale of 1 (not at all likely to cheat) to 10 (very likely).
These were voices of strangers the participants didn't know, with no content about their relationships being revealed, just a voice counting from one to 10. And yet those recordings revealed volumes about their personal lives.
"We found that participants indeed rated the voices of those who had a history of cheating as more likely to cheat," the researchers reported. More likely than not, Hughes noted, participants correctly identified the cheaters from the non-cheaters.
Even when the speakers' pitch was manipulated, it didn't seem to play a factor - except for the lower-pitched female voices, which men rated as more likely to cheat. (This could be because low female voices are perceived as sexier or more flirtatious, Hughes said in a phone interview.)
Women were influenced by perception as well; they were more likely to rate men as being untrue to their partners but weren't necessarily more accurate in those estimations. This might be because women are more suspicious of men than men are of women, the study noted; men also are more likely to self-report having cheated on a partner.
The study's researchers couldn't determine why humans are so good at reading one another's voices, just that we are. "While we cannot exactly pinpoint all the features about a voice that our perceptual system is using to make this assessment, we know that pitch plays a role, but does not represent the entire picture," the study concluded.
"Other vocal cues such as clarity of articulation may have also contributed to perceptions of infidelity," the study said. "For example, masculine males tend to display less clarity in their speech and show phonetic patterns indicative of masculinity, which in turn could be associated with infidelity threat."
It's also possible, Hughes said, that certain personality traits - such as extroversion - that are evident in a voice, could signal a greater likelihood of being unfaithful. "Extroverts show greater variation in fundamental frequency, greater voice quality, and fewer silent pauses ... and high extroversion strongly predicts infidelity," the study found.
Interesting stuff, but how does this study relate to real life? Because voices contain so much information about a person, Hughes recommends always speaking to a romantic prospect before meeting up that first time.
"It would be fine to be a blind date, but don't go on a deaf date," Hughes says. And, yes, going on a first date where you matched online and made all the arrangements via text qualifies as a "deaf date."
