For the interlocutors by cons is another story, it cracks, it sizzles, communications are chopped short, it's unbearable. There is no isolation from ambient noise, the contrary is more environment entant my voice!
My old headset noname came out of the closet until a better model (but also more expensive bcp: M1100).
Very disappointed Plantronics product.
Concerning the maintenance system in the ear, we must adjust the silicone tip to have no pain, if it is in place it holds well and does not feel.