The Autonomous Sensory Meridian Response (ASMR) Research & Support site defines the phenomenon as, "a physical sensation characterized by a pleasurable tingling that typically begins in the head and scalp, and often moves down the spine and through the limbs." Various stimuli can trigger the sensation -- certain kinds of sights, sounds, and situations. It's sometimes referred to as a "braingasm".
I'm not sure whether ASMR is considered to be a scientifically verified phenomenon. Nevertheless, there's a sizable community of people who actively seek the sensation, and they post videos on youtube designed to trigger it. That's why, if you wade deep enough into the depths of youtube, you'll eventually come across a whole slew of odd ASMR-trigger videos, such as this one of the sounds of gift wrapping
I believe that the whisper videos I posted about yesterday are related to this ASMR phenomenon -- because whispering can be an ASMR trigger. That is, most people simply find it annoying to have to strain to hear someone whispering, but there are a few who are getting a tingly, braingasm feeling from it.