Sounds like environment is a bigger problem for you than the headset. Noise cancelling and microphone sensitivity can be tricky to get to function well if there is too much background noise. Open call centers where the person on the other end can hear all the other people in the room talking in the background for instance. If that's the environment, I don't know how much luck you are going to have. The microphone would have to be set to such a low volume the person using it may have to all but shout.
We've tried using the office 365 transcritption system and when used in an office environment, i've been told that the existing headsets etc pick up too much background noise and picks up what other people are saying. Does anyone have any recommendation for a sensibly priced (up to £100? if able) headset that would be helpful here and really reduce the background noise.