The study found that people found it hard to concentrate on half of a mobile phone conversation.(telegraph.co.uk)
Why overhearing mobile phone conversations is so annoying
The reason why people find overheard mobile phone conversations so annoying has been solved by scientists.
Researchers discovered that it takes more effort for the brain to understand only half a conversation or a “halfalogue” compared with a full dialogue between two people.
Scientists at Cornell University, New York, found that people could not predict what the person talking into the mobile would say next - because they had not heard the last words from the person on the other end of the phone.
The brain has to work twice as hard to understand the conversation and fill in the blanks, requiring more attention and making it harder to shut out.
The conclusions in the study, published in the journal Psychological Science, show why many of us find it annoying overhearing people talking loudly on their mobile phone in the office, on a train or in a car
"It's unbelievably irritating to overhear someone on a cell phone," said Lauren Emberson, the study co-author.
"It's harder to tune out, you can't pull your attention away from it and you're more distracted by it.
"We have less control to move away our attention from half a conversation (or halfalogue) than when listening to a dialogue.
The postgraduate psychology student added: “Since halfalogues really are more distracting and you can't tune them out, this could explain why people are irritated.
"When you hear half of a conversation, you get less information and you can't predict as well. It requires more attention."
She said when people try to eavesdrop they try and make sense of snippets of conversation and predict what speakers will say next.
The findings was based on research involving 41 college students who did concentration exercises including tracking moving dots, while hearing one or both parties during a mobile 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 mobile phone conversation affects the attention we use in our daily tasks, including driving, she added.
"These results suggest that a driver's attention can be impaired by a passenger's mobile phone conversation," she added.
There are about 4.6 billion global mobile subscribers, according to the International Telecommunications Union, a U.N. agency, which is the equivalent to about two-thirds of the world's population.
The study recommended similar studies should be conducted with driving simulators.