ASMR: How sound is being used as a stress reliever
You may not have heard about ASMR but type it into a search engine and you get more than 11 million responses, many of them videos.
They are designed for relaxation and for many viewers can cause a distinctive and pleasurable tingling sensation in the head.
Scientists are now investigating the phenomenon of Autonomous Sensory Meridian Response in more depth, as Nick Higham reports.
16 Dec 2015