I would really love a chair with the isolating and focus enhancing properties of a cave chair combined with the softness, reclined nature, and ability to sink in like a papasan chair. This is a simple design I threw together in isometric and in section view.

I'm no chair engineer, but in my mind, the outer shell would be constructed of a foam cored wall with some type of a coarsely woven fabric encompassing it; both to provide soft inviting shapes and to dampen out the noise from without and within.

the seat and backrest should be wrapped in the same textile covering, but the core should be some type of rigid yet pliable cushion , possibly memory foam or a foam with similar properties. The goal in this area is to provide support when not bring pressured too much, but to allow compression to recline when one's full weight is leaned on it.