SFL - Semi-focused listening -- listening is the central but not only activity (sitting in front of audio, listening but also reading, playing games, emailing, etc.)
CL - Casual listening -- listening to music but also involved in equally important tasks (cooking, doing dishes, laundry, etc.)
@hilde45 You have these two the wrong way around. Reading , playing games involve intellectual input, that get's in the way of listening. I know, I often listen while reading. Cooking, and especially dishes, laundry, need no significant intellectual input, so do not interrupt the connection between brain and music. My wife listens to talk radio while gardening and follows it perfectly.