I worked in tech support for a large computer manufacturer a couple years back. After some time taking calls, I was promoted to a QA position where my job was… to listen to the recorded calls and evaluate the technician’s performance.
Not every call was recorded. There were far too many calls to do that. While I was there the recordings were never used for anything other than to evaluate the technicians. And my amusement.
Senior techs and managers had the capability to monitor calls live, something I also did as a mentor. Usually the mentor is sitting right next to the trainee with a muted headset. Sometimes the trainee listens in on the mentor for a day or two.
It didn’t happen much, but sometimes the trainee would crash and burn so badly on a real call that the mentor would drop onto the line and get the customer fixed up.