At the end of each shift there is a debriefing session for 5 no s or so which is always useful to find out how the evening went as a whole as sometimes when you are doing a small role you haven't got an overview of how the event has gone.
Only feed back you get is from supervisor on site otherwise no upper management talk's to you not even to see how you are doing as a new starter. it's just text or email can you pick and let us know what shift's you can do.
Sometimes their is a staff briefing at the start of the shift. Very rare any individual feedback is given.
They do not provide you with any feedback and tell you not to ask because they cannot give you one at this moment.
There is very little feedback, if any form local or higher management.
Through email mainly, though we do complete e-learning regularly which has feedback forms attached.