ASMR

Autonomous Sensory Meridian Response, also called "the tingles" and "head orgasm", has been getting a lot of attention over on Reddit. The phenomenon has also generated an entire genre of whispery videos that trigger the response in a subset of listeners. ASMR is described as an extremely pleasant sensation in response to certain stimuli. From Vice:

 Maria, aka GentleWhispering (she didn’t want me to use her last name), has been triggered by everything from accented whispers to scratching grainy surfaces to being tickled when she was in kindergarten. During a Skype conversation I had with her, she described ASMR as feeling like “bubbles in your head,” and compared it to getting a scalp massage, but the sensation is on the inside. She went on: “It’s like a little explosion, and then just little sparkles and little stars going down [your back]. Depending on the strength of the trigger, it might just go into the top of the spine of the shoulders, but sometimes it goes down to your arms and legs, and other parts. Mostly, if you get it in your leg, it’s really exciting!”

 When I watch the videos, they're very pleasant, but I don't quite get the full experience Maria and the Reddit group describe. Other people describe the triggering videos as "the most boring thing ever", which indicates that it's might be a hyperactive reward response to low intensity sensory input. Fascinating stuff--someone should do a study.