The best way to pick up on a person's emotions is to close your eyes and listen to them talk, a new study suggests.
People tend to read emotions more accurately when they listen and don't look.
The study, published in the American Psychological Association's journal American Psychologist, found that blocking out other senses and using voice-only communication "elicits higher rates of empathic accuracy".
The author describes a series of five experiments involving almost 1,800 participants from the US.
In each experiment, participants were asked either to interact with another person or were presented with an interaction between two other people.
Participants were either asked to listen and not look, to look but not listen and in some tests they were able to do both.
In another experiment, participants listened to a computerised voice reading a transcript of an interaction.
Researchers found that people who only listened to the interactions were able to more accurately identify the emotions being experienced than others.
The test with the computerised voice led to the worst ability to accurately detect emotion.
"Social and biological sciences over the years have demonstrated the profound desire of individuals to connect with others and the array of skills people possess to discern emotions or intentions. But, in the presence of both will and skill, people often inaccurately perceive others' emotions," said author Michael Kraus, assistant professor of organisational behaviour at Yale University.
"Our research suggests that relying on a combination of vocal and facial cues, or solely facial cues, may not be the best strategy for accurately recognising the emotions or intentions of others.
"Listening matters. Actually considering what people are saying and the ways in which they say it can, I believe, lead to improved understanding of others at work or in your personal relationships."
He added that many previous tests on emotional intelligence rely on people's perceptions of faces.
"What we find here is that perhaps people are paying too much attention to the face - the voice might have much of the content necessary to perceive others' internal states accurately," he said.
"The findings suggest that we should be focusing more on studying vocalisations of emotion."
One possible explanation is that people having more practice using facial expressions to mask emotions. Another is that when people engage in two tasks at the same time - such as watching and listening - it may inhibit a person's performance on both tasks, he said.