A:AnswerI just had a similar problem and have to return them. They only worked a few days but I was already hearing a issue for days now where the left ear would not work then pop and work for a while.
A:AnswerYou have to download the manual from the website, follow instructions. Cords are very specific; you cannot use any cord universally. I had the same problem; the cords are marked for specific device.
A:AnswerI believe you're asking about hearing yourself on the headset as you speak? If so, then yes. I can hear myself while I speak into the mic. Makes it easier to control your voice volume in the middle of the night.
A:AnswerI use these headsets for work and I do a lot of online training. The headsets have not caused any heat build-up that I have recognized. I use them for several hours at a time, and they remain comfortable.