As the unpaid volunteers were recruited via adverts with text such as “Do you experience ‘hearing motion?’”, it’s certainly possible that there was a self-selection bias. But, on enrolment, the paid participants did not know what the study was about, so, in theory, they should be more representative of the general population. Thirty-one per cent of this paid group (an even higher percentage, in fact, than in the bigger, unpaid group) reported past experience of vEAR. When it came to the survey results, anyone who rated half of the videos at greater than or equal to 3 was identified as experiencing vEAR. Just over 20 per cent of the paid participants fell into this category. Taken with the self reports of past experience of vEAR, the findings suggest that the phenomenon is far from rare. The higher-rated videos often depicted relatively familiar events that are reliably associated with particular sounds (like fists hitting a punchbag), suggesting that an understanding of what’s happening in the scene was involved in causing the illusory sounds. - neurosciencenews.com