Open-back headphones let those around you know exactly how loud you are listening to music and, more importantly, what your musical playlist currently offers. However, they also allow the heat that inevitably builds up between the ear and ear cup to escape, enabling longer and more comfortable listening sessions.
Open-back headphone models are particularly recommended when the sound emitted by the headphones is not an issue. Therefore, an open design is ideal for home use, where you can fully enjoy an extremely open and spatial sound image without unwanted listeners, which closed models cannot offer.