Researchers, led by the University of Michigan, have carried out the study and found that the key of talking someone round to your view depends on how fast you speak, the Daily Express reported.

In fact, the researchers have based their findings on an analysis of 1,400 cold sales calls which they monitored.

Cold callers who spoke moderately quickly — at a rate of around 3.5 words a second or 210 a minute — were the most successful at convincing people to take part in a telephone survey, the findings revealed.

However, speaking too quickly made people feel the caller was trying to fool them, while those who talked too slowly were branded stupid, the study found. The researchers also found those who paused four or five times a minute were more successful.

Dr Jose Benki, who led the research, said using brief pauses gave the impression the speaker was talking from the heart rather than reading off a script.