Neuroscientists at the University of California Berkeley put electrodes inside the skulls of brain surgery patients to monitor information from their temporal lobe, which is involved in the processing of speech and images.
As the patient listened to someone speaking, a computer program analysed how the brain processed and reproduced the words they had heard.
The scientists believe the technique could also be used to read and report what they were thinking of saying next.
In the journal PLoS Biology, they write that it takes attempts at mind reading to ‘a whole new level’.
A computer programme analysed the activity from the electrodes, and reproduced the word they had heard or something very similar to it at the first attempt.
Co-author Brian Pasley said there is already mounting evidence that ‘perception and imagery may be pretty similar in the brain’.
Therefore with more work, brain recordings could allow scientists to ‘synthesise the actual sound a person is thinking, or just write out the words with a type of interface device.’
Their study also shows in sharp relief how the auditory system breaks down sound into its individual frequencies – a range of around 1 to 8,000 Hertz for human speech.
Pasley told ABC News: ‘This study mainly focused on lower-level acoustic characteristics of speech. But I think there’s a lot more happening in these brain areas than acoustic analysis’.
He added: ‘We sort of take it for granted, the ability to understand speech. But your brain is doing amazing computations to accomplish this feat.’