Sep 17, 2010 07:53 GMT  ·  By

As most of you already know, overhearing conversations people carry on their mobile phones while in public places can be extremely annoying, and a new study show why.

When two people have a conversation in the background, those overhearing it tend to get less annoyed because they unconsciously hear both the questions and answers, or the lines and replies.

But when a phone conversation is going on in the background, we only hear half of what is being discussed, more precisely the things the person close to us is saying.

This is a lot more distracting for our brains than hearing a full conversation, the new research shows, and this is why many get so annoyed in such a situation.

The investigators go on to say that the main reason why a background cell phone conversation catches the attention of people around is that it's random. In other words, those overhearing it don't know what to expect with the coming reply, and that is irritating.

When hearing a full conversation, the flow of the discussion is registered in the brain, which can then set itself to ignore it. This is how we are able to communicated in restaurants, subways, and other crowded locations.

“When we get less information, we're impaired. We can't use this information to anticipate what's going to be said next and so it's much harder on our brains,” says Lauren Emberson.

The expert is holds an appointment as a psychologist at the Cornell University, in Ithaca, New York. She is also the lead author of the study, which is detailed in the latest issue of the top-rated journal Psychological Science.

The scientist goes on to say that prediction is key to our ability to understand what is going on in the world around us. It is also what keeps us prepared, and what makes us unlikely to remain eternally surprised.

“We use patterns in our environment to predict what's going to happen next, and this helps us a huge amount in the context of language,” Emberson reveals.

In the case of cell phone conversation, this ability to predict what is going to be said is lost, and the brain goes into alert, emerging people into whatever conversations are being carried out in the background.

This is perceived at a conscious level as a nuisance, and some people get angrier than others. The best thing to do is for those who speak on their cell phones to turn the volume of their speech down.

Otherwise, they risk unpleasant situations with the other people they share the room, bus, train or plane with, LiveScience reports.