I suspect all ear plugs will always cause tinnitus. Having sound emitted so close to your ear drum is not a good idea. Not to mention that often, air cannot escape, which increase energy and/or air pressure inside the ear canal. A better alternative would be to have helicopter-type headset (not as much soundproof, though), so that you won't increase volume to mask surrounding noise in public transport or outside.
I thought the specific purpose of a helicopter headset was noise isolation, given the high noise levels of rotorcraft.
I was talking about a headset that would be similar to a helo headset, without as much sound isolation.