New research has uncovered the reason why hearing other people's mobile conversations can be so irritating.
According to the Daily Telegraph scientists at Cornell University found that the human brain finds it twice as hard to understand a one-sided conversation as a normal one.
One of the major reasons was that listeners couldn't predict what the caller would say next as they has not heard the last words of the person on the other end of the line.
The extra mental attention required to fill in the conversational gaps meant the subjects of the study found it almost impossible not to be distracted by the conversation.
The report recommended that further studies were carried out to look into the potentially dangerous effect that passenger phone conversations could have on car drivers.
