Earmuff mode to reduce audio volume from sources not in view

[Armored-Dragon]

A common feature in a lot of platforms is a "Earmuff mode". This essentially works as a way to reduce over stimulation or make it easier to focus on conversations happening right in front of you. When you look away from a person, their audio gets reduced (mostly) regardless of their distance to you.

This illustration shows what I mean. The center dot represents the client, us. The other black dots represents other players. The green zone is audio that functions as it currently does without any audio limiter applied. The red zone represents the area that will have muffled voice audio (or global audio?).

[ksuprynowicz]

I really like that idea. Maybe it could be done by switching to a custom Head-related transfer function when it's enabled?