No offense to the folk at Plantronics, but I just can't use their stuff. I am almost completely deaf in my left ear from the military, and due to some other neurological issues, I have to basically read lips most of the time. If there are multiple conversations, I am pretty much deaf as a post. If someone wants to have dinner in a noisy restaurant, they might as well have it in a chain-saw repair shop.
These really help a lot, and I can function in an office environment now.
Hope that helps.