ASMR is one of those things that is often difficult to explain because it is more of a feeling than anything else. ASMR stands for Autonomous Sensory Meridian Response and at its most simplest can be defined as a tingly sensation that is most often felt at the back of the head although it can also be felt down the back, arms and even the legs. That tingly feeling comes about due to certain audio or visual triggers like a tapping sound or the soft patter of the rain, the sound of someone whispering or watching someone performing a mundane repetitive task. It's a very soothing feeling and very relaxing.