‘If anyone can say this 10 times quickly, they get a prize,’ she said.

The tongue twister study, presented at the annual meeting of the Acoustical Society of America in San Francisco, was conducted to shed light on the brain’s speech-planning processes.

‘When things go wrong, that can tell you something about how the typical, error-free operation should go,’ said Dr Shattuck-Hufnagel.

Spoken too quickly, certain combinations of sounds appear to make people lose control of their mouths.

Often, one sound seems to replace another. For instance, ‘toy boat’ becomes ‘toy boyt’ and ‘top cop’ becomes ‘cop cop’.

But when the researchers recorded misspoken sounds and analysed them they found that the mistakes could be more subtle.

At least some of the time, tongue twister mix-ups were not one sound or another, but appeared to be something in between.

In the ‘top cop’ example, sometimes the ‘t’ and ‘c’ seemed to arrive at almost the same time (‘t’kop’) and sometimes there was a delay between the two sounds with space for a vowel (‘tah-kop’).

The scientists studied two categories of tongue twister, simple lists of paired words, such as ‘top cop’ and whole sentences.

They found that in the word list tongue twisters there was a preponderance of ‘t’kop’ type errors. In contrast, sentences produced more ‘tah-kop’ mistakes that included a short vowel after the initial consonant.

One possible clue to what is happening may be the regular rhythm of the word lists compared with the more irregular timing of the sentences, said Dr Shattuck-Hufnagel.

But there appeared to be some overlap in the processes used to produce both types of speech.

Well, could that truly be the world’s tongue twister? I bet there are more. What do you think?