ASMR is usually precipitated by stimuli referred to as 'triggers'. ASMR triggers, which are most commonly acoustic and visual, may be encountered through the interpersonalinteractions of daily life. Additionally, ASMR is often triggered by exposure to specific audio and video. Such media may be especially made with the specific purpose of triggering ASMR, or originally created for other purposes and later discovered to be effective as a trigger of the experience.

Exposure to stimuli that can trigger ASMR, as reported by those who experience it, include the following:

• Listening to a softly spoken or whispering voice
• Listening to quiet, repetitive sounds resulting from someone engaging in a mundane task such as turning the pages of a book
• Watching somebody attentively execute a mundane task such as folding towels
• Receiving altruistic tender personal attention

Furthermore, watching and listening to an audiovisual recording of a person performing or simulating the above actions and producing their consequent and accompanying sounds is sufficient to trigger ASMR for the majority of those who report susceptibility to the experience.

You can read more about it on the wiki page. Very fascinating! If you've experienced this, tell us what was it that gave you that warm, tingly feeling? Similar to goose bumps, but sort of in the back of your head and down your neck and back.