ASMR stands for autonomous sensory meridian response, and it refers to the tingling sensations certain people feel when they hear specific sounds, or 'triggers', like gentle tapping on an object, the tearing of paper or whispering. There's an infinite number of triggers and seemingly an infinite number of YouTube channels dedicated to the craft, which is meant to relax its listeners and help them sleep. Here, we've rounded up eight of our favourite channels, including top dogs in the industry and a few lesser-known names.