Other headphones companies such as Marley have used hemp fibers in some of their materials before, but Grado is relying on it to help create the actual sound. The Hemp Headphones use Grado’s familiar open-back design. Compared to a typical pair of closed-off headphones, they let in more ambient noise and expand the soundstage to make it feel like the music is coming from all around the room rather than pumping directly into your ears. That open design relies heavily on the resonating materials to create its signature sound. As with any open-air headphone, however, that means music can also escape into the world around you as you listen.