I’ve looked at headset/phone merchants but I’ve seen such a thing. Has anyone seen?
Some people are REALLY loud and it hurts one’s ear - I move the phone an inch from my ear. Some people can barely be heard.
Plantronics used to make one called “Clear Call” or similar. In fact if you are looking for something phone or headset related, I would start with Plantronics.
Most of the call centers I’ve seen have a large device that does this for incoming calls already. I haven’t ever used one personally.