Have you heard of ASMR?
Whispery, clicky, crinkly videos are massive on YouTube - racking up millions of views.
The idea is that these sounds elicit a certain tingly, calming sensation in some people.
So what is ASMR and what does the science tell us about it?
Is it real … or pseudoscience? And why do some people get the opposite reaction – irritation rather than these pleasant tingles?