Ever wonder why overhearing a phone conversation is so annoying? American researchers think they have found the answer.
Whether it is the office, on a train or in a car, only hearing half of a conversation drains more attention and concentration than when overhearing two people talking, according to scientists at Cornell University.
"We have less control to move away our attention from half a conversation, or 'halfalogue', than when listening to a dialogue," says Lauren Emberson, a co-author of the study that will be published in the journal Psychological Science.
"Since halfalogues really are more distracting and you can't tune them out, this could explain why people are irritated," she says.
According to the Australian Mobile Telecommunications Association there are more than 22 million mobile phones in Australia - one for each person.
Worldwide, there are about 4.6 billion mobile phones, according to the International Telecommunications Union, a UN agency. The number is equal to about two-thirds of the world's population, leaving few corners of the globe where public spaces are free of mobile-tethered babblers.
China has the most mobile phone users with 634 million, followed by India with 545 million and the United States with 270 million, figures from the US Central Intelligence Agency show.
Piecing together snippets
Emberson says people try to make sense of snippets of conversation and predict what speakers will say next.
"When you hear half of a conversation, you get less information and you can't predict as well," she said. "It requires more attention."
The findings by Emberson and her co-author Michael Goldstein are based on research involving 41 college students who did concentration exercises, like tracking moving dots, while hearing one or both parties during a phone conversation.
The students made more errors when they heard one speaker's side of the conversation than when overheard the entire dialogue.
The study shows that overhearing a phone conversation affects the attention we use in our daily tasks, including driving, says Emberson.
"These results suggest that a driver's attention can be impaired by a passenger's cell phone conversation," according to the study.
It recommends similar studies should be conducted with driving simulators.